CVE-2026-31709

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-31709", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.133Z", "datePublished": "2026-05-01T13:56:06.522Z", "dateUpdated": "2026-10-19T19:06:06.980Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:24:44.209Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: validate the whole DACL before rewriting it in cifsacl\n\nbuild_sec_desc() and id_mode_to_cifs_acl() derive a DACL pointer from a\nserver-supplied dacloffset and then use the incoming ACL to rebuild the\nchmod/chown security descriptor.\n\nThe original fix only checked that the struct smb_acl header fits before\nreading dacl_ptr->size or dacl_ptr->num_aces. That avoids the immediate\nheader-field OOB read, but the rewrite helpers still walk ACEs based on\npdacl->num_aces with no structural validation of the incoming DACL body.\n\nA malicious server can return a truncated DACL that still contains a\nheader, claims one or more ACEs, and then drive\nreplace_sids_and_copy_aces() or set_chmod_dacl() past the validated\nextent while they compare or copy attacker-controlled ACEs.\n\nFactor the DACL structural checks into validate_dacl(), extend them to\nvalidate each ACE against the DACL bounds, and use the shared validator\nbefore the chmod/chown rebuild paths. parse_dacl() reuses the same\nvalidator so the read-side parser and write-side rewrite paths agree on\nwhat constitutes a well-formed incoming DACL."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - The vulnerable DACL is supplied by an SMB server over network SMB/CIFS ACL query responses and parsed by the Linux SMB client in kernel context. A malicious or compromised SMB server can deliver the crafted security descriptor over TCP.\nAC:L - After the client reaches the CIFS ACL path, the attacker controls the DACL offsets, sizes, ACE count, and ACE bytes in the server response. There is no race or condition outside attacker control needed to trigger the malformed ACE walk.\nPR:N - The attacker needs no privileges on the victim system; they only need to act as or control the SMB server that the client uses. Local chmod/chown permission checks apply to the victim-side process, not to the remote attacker.\nUI:R - Exploitation requires the victim system or an automated victim workflow to mount/use the SMB share and issue metadata operations such as stat, chmod, chown, or chgrp. The server cannot trigger this parser without a client request.\nS:U - The vulnerable component and the impacted resource are the same Linux kernel security authority on the SMB client. This is not a VM escape, IOMMU bypass, or cross-authority boundary violation.\nC:H - The malformed DACL can drive out-of-bounds reads while copying ACE/SID data, and rewritten ACL data can be sent back to the malicious server. Under the required high-severity tie-break rule, this is treated as high confidentiality impact.\nI:H - The chown/chgrp rewrite path can copy attacker-influenced ACEs into a newly allocated security descriptor beyond the size derived from the declared DACL, creating kernel heap memory corruption. Such corruption is potentially exploitable for arbitrary write or code execution.\nA:H - Malformed server-controlled ACL structures can drive out-of-bounds kernel memory access during ACL parsing or rewriting. Even without full exploitation, this can crash or oops the kernel."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/client/cifsacl.c"], "versions": [{"version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "lessThan": "b8603d9ae6c9087662b098619996bc4a8064319d", "status": "affected", "versionType": "git"}, {"version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "lessThan": "c2abdebf72000a64603ced84d36ccbd164f11391", "status": "affected", "versionType": "git"}, {"version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "lessThan": "8e47d297e7cf9a6029a0d38e7b22faba7d7aaf12", "status": "affected", "versionType": "git"}, {"version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "lessThan": "d92f3f0b22414e7515696a02224d0af55e3004a3", "status": "affected", "versionType": "git"}, {"version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "lessThan": "ff0ca46b13b9ef6edbcd238a3b6caacfef8ba0e5", "status": "affected", "versionType": "git"}, {"version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "lessThan": "b78db9bddc84136f6a0bb49e8883cf200dfb87a8", "status": "affected", "versionType": "git"}, {"version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "lessThan": "0a8cf165566ba55a39fd0f4de172119dd646d39a", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/client/cifsacl.c"], "versions": [{"version": "5.12", "status": "affected"}, {"version": "0", "lessThan": "5.12", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.210", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.176", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.140", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.86", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.35", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.2", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "5.15.210"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "6.1.176"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "6.6.140"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "6.12.86"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "6.18.35"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "7.0.2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "7.1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/b8603d9ae6c9087662b098619996bc4a8064319d"}, {"url": "https://git.kernel.org/stable/c/c2abdebf72000a64603ced84d36ccbd164f11391"}, {"url": "https://git.kernel.org/stable/c/8e47d297e7cf9a6029a0d38e7b22faba7d7aaf12"}, {"url": "https://git.kernel.org/stable/c/d92f3f0b22414e7515696a02224d0af55e3004a3"}, {"url": "https://git.kernel.org/stable/c/ff0ca46b13b9ef6edbcd238a3b6caacfef8ba0e5"}, {"url": "https://git.kernel.org/stable/c/b78db9bddc84136f6a0bb49e8883cf200dfb87a8"}, {"url": "https://git.kernel.org/stable/c/0a8cf165566ba55a39fd0f4de172119dd646d39a"}], "title": "smb: client: validate the whole DACL before rewriting it in cifsacl", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"affected": [{"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:10.2"], "defaultStatus": "affected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 10", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:6.12.0-211.20.1.el10_2", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux_eus:10.0"], "defaultStatus": "affected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 10.0 Extended Update Support", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:6.12.0-55.77.1.el10_0", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:enterprise_linux:8::nfv"], "defaultStatus": "affected", "packageName": "kernel-rt", "product": "Red Hat Enterprise Linux 8", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:4.18.0-553.126.1.rt7.467.el8_10", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:8"], "defaultStatus": "affected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 8", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:4.18.0-553.126.1.el8_10", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:enterprise_linux:9", "cpe:/o:redhat:enterprise_linux:9"], "defaultStatus": "affected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 9", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:5.14.0-687.12.1.el9_8", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:rhel_e4s:9.2"], "defaultStatus": "affected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:5.14.0-284.174.1.el9_2", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:rhel_e4s:9.2::nfv"], "defaultStatus": "affected", "packageName": "kernel-rt", "product": "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:5.14.0-284.174.1.rt14.459.el9_2", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:rhel_e4s:9.4"], "defaultStatus": "affected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:5.14.0-427.129.1.el9_4", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:rhel_eus:9.6"], "defaultStatus": "affected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 9.6 Extended Update Support", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:5.14.0-570.119.1.el9_6", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:6"], "defaultStatus": "unaffected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 6", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:7"], "defaultStatus": "unaffected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 7", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:7"], "defaultStatus": "unaffected", "packageName": "kernel-rt", "product": "Red Hat Enterprise Linux 7", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:9"], "defaultStatus": "affected", "packageName": "kernel-rt", "product": "Red Hat Enterprise Linux 9", "vendor": "Red Hat"}], "datePublic": "2026-05-01T00:00:00.000Z", "descriptions": [{"lang": "en", "value": "A flaw was found in the Linux kernel's Server Message Block (SMB) client, specifically within the cifsacl functionality. A malicious SMB server could provide a malformed Discretionary Access Control List (DACL) that claims to contain more Access Control Entries (ACEs) than are actually present. This insufficient validation allows the kernel to read or copy data beyond the intended memory boundaries, leading to memory corruption. This could potentially result in information disclosure or a denial of service."}], "metrics": [{"other": {"content": {"namespace": "https://access.redhat.com/security/updates/classification/", "value": "Important"}, "type": "Red Hat severity rating"}}, {"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "format": "CVSS"}], "problemTypes": [{"descriptions": [{"cweId": "CWE-1288", "description": "Improper Validation of Consistency within Input", "lang": "en", "type": "CWE"}]}], "references": [{"tags": ["vdb-entry", "x_refsource_REDHAT"], "url": "https://access.redhat.com/security/cve/CVE-2026-31709"}, {"name": "RHBZ#2464476", "tags": ["issue-tracking", "x_refsource_REDHAT"], "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2464476"}, {"tags": ["x_sadp-csaf-vex"], "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31709.json"}, {"tags": ["vendor-advisory", "x_refsource_REDHAT"], "url": "https://access.redhat.com/errata/RHSA-2026:24343"}, {"tags": ["vendor-advisory", "x_refsource_REDHAT"], "url": "https://access.redhat.com/errata/RHSA-2026:23329"}, {"tags": ["vendor-advisory", "x_refsource_REDHAT"], "url": "https://access.redhat.com/errata/RHSA-2026:22940"}, {"tags": ["vendor-advisory", "x_refsource_REDHAT"], "url": "https://access.redhat.com/errata/RHSA-2026:23237"}, {"tags": ["vendor-advisory", "x_refsource_REDHAT"], "url": "https://access.redhat.com/errata/RHSA-2026:23224"}, {"tags": ["vendor-advisory", "x_refsource_REDHAT"], "url": "https://access.redhat.com/errata/RHSA-2026:21556"}, {"tags": ["vendor-advisory", "x_refsource_REDHAT"], "url": "https://access.redhat.com/errata/RHSA-2026:21706"}, {"tags": ["vendor-advisory", "x_refsource_REDHAT"], "url": "https://access.redhat.com/errata/RHSA-2026:21745"}, {"tags": ["vendor-advisory", "x_refsource_REDHAT"], "url": "https://access.redhat.com/errata/RHSA-2026:22900"}], "solutions": [{"lang": "en", "value": "RHSA-2026:24343: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux BaseOS EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0), Red Hat Enterprise Linux Real Time EUS (v. 10.0), Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0)"}, {"lang": "en", "value": "RHSA-2026:23329: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Real Time (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10)"}, {"lang": "en", "value": "RHSA-2026:22940: Red Hat Enterprise Linux AppStream E4S (v.9.2), Red Hat Enterprise Linux BaseOS E4S (v.9.2)"}, {"lang": "en", "value": "RHSA-2026:23237: Red Hat Enterprise Linux AppStream E4S (v.9.4), Red Hat Enterprise Linux BaseOS E4S (v.9.4), Red Hat Enterprise Linux Real Time E4S (v.9.4), Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4)"}, {"lang": "en", "value": "RHSA-2026:23224: Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat Enterprise Linux BaseOS EUS (v.9.6), Red Hat Enterprise Linux Real Time EUS (v.9.6), Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6)"}, {"lang": "en", "value": "RHSA-2026:21556: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9)"}, {"lang": "en", "value": "RHSA-2026:21706: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8)"}, {"lang": "en", "value": "RHSA-2026:21745: Red Hat Enterprise Linux NFV (v. 8), Red Hat Enterprise Linux RT (v. 8)"}, {"lang": "en", "value": "RHSA-2026:22900: Red Hat Enterprise Linux Real Time E4S (v.9.2), Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)"}], "timeline": [{"lang": "en", "time": "2026-05-01T00:00:00.000Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-05-01T00:00:00.000Z", "value": "Made public."}], "title": "kernel: smb: client: validate the whole DACL before rewriting it in cifsacl", "workarounds": [{"lang": "en", "value": "To mitigate this issue, if SMB client functionality is not required, the `cifs` kernel module can be blacklisted to prevent it from loading. This can be achieved by creating a modprobe configuration file.\n\n1. Create a file named `/etc/modprobe.d/disable-cifs.conf` with the following content:\n ```\n install cifs /bin/true\n blacklist cifs\n ```\n2. Regenerate the initramfs to ensure the change takes effect on boot:\n ```bash\n dracut -f -v\n ```\n or for systems using `mkinitrd`:\n ```bash\n mkinitrd -f /boot/initramfs-$(uname -r).img $(uname -r)\n ```\n3. A system reboot is required for the changes to take effect.\n\nWarning: Disabling the `cifs` module will prevent the system from mounting SMB/CIFS shares. Ensure this functionality is not critical before applying this mitigation.\n\nrefer: https://access.redhat.com/solutions/4117281"}], "x_adpType": "supplier", "x_generator": {"engine": "sadp-cli 1.0.0"}, "providerMetadata": {"orgId": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "shortName": "redhat-SADP", "dateUpdated": "2026-07-15T01:08:58.337Z"}}, {"x_adpType": "supplier", "providerMetadata": {"orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-10-15T01:18:05.846Z"}, "affected": [{"vendor": "Siemens", "product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem", "versions": [{"status": "affected", "version": "0", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}], "references": [{"url": "https://cert-portal.siemens.com/productcert/html/ssa-784472.html"}]}, {"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-31709", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T15:12:47.844968Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-125", "description": "CWE-125 Out-of-bounds Read"}]}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-19T19:06:06.980Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "kernel: smb: client: validate the whole DACL before rewriting it in cifsacl", "metrics": [{"other": {"type": "Red Hat severity rating", "content": {"value": "Important", "namespace": "https://access.redhat.com/security/updates/classification/"}}}, {"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}}], "affected": [{"cpes": ["cpe:/o:redhat:enterprise_linux:10.2"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 10", "versions": [{"status": "unaffected", "version": "0:6.12.0-211.20.1.el10_2", "lessThan": "*", "versionType": "rpm"}], "packageName": "kernel", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/o:redhat:enterprise_linux_eus:10.0"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 10.0 Extended Update Support", "versions": [{"status": "unaffected", "version": "0:6.12.0-55.77.1.el10_0", "lessThan": "*", "versionType": "rpm"}], "packageName": "kernel", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:enterprise_linux:8::nfv"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8", "versions": [{"status": "unaffected", "version": "0:4.18.0-553.126.1.rt7.467.el8_10", "lessThan": "*", "versionType": "rpm"}], "packageName": "kernel-rt", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/o:redhat:enterprise_linux:8"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8", "versions": [{"status": "unaffected", "version": "0:4.18.0-553.126.1.el8_10", "lessThan": "*", "versionType": "rpm"}], "packageName": "kernel", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:enterprise_linux:9", "cpe:/o:redhat:enterprise_linux:9"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9", "versions": [{"status": "unaffected", "version": "0:5.14.0-687.12.1.el9_8", "lessThan": "*", "versionType": "rpm"}], "packageName": "kernel", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhel_e4s:9.2"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions", "versions": [{"status": "unaffected", "version": "0:5.14.0-284.174.1.el9_2", "lessThan": "*", "versionType": "rpm"}], "packageName": "kernel", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhel_e4s:9.2::nfv"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions", "versions": [{"status": "unaffected", "version": "0:5.14.0-284.174.1.rt14.459.el9_2", "lessThan": "*", "versionType": "rpm"}], "packageName": "kernel-rt", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhel_e4s:9.4"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions", "versions": [{"status": "unaffected", "version": "0:5.14.0-427.129.1.el9_4", "lessThan": "*", "versionType": "rpm"}], "packageName": "kernel", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/a:redhat:rhel_eus:9.6"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9.6 Extended Update Support", "versions": [{"status": "unaffected", "version": "0:5.14.0-570.119.1.el9_6", "lessThan": "*", "versionType": "rpm"}], "packageName": "kernel", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}, {"cpes": ["cpe:/o:redhat:enterprise_linux:6"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 6", "packageName": "kernel", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/o:redhat:enterprise_linux:7"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 7", "packageName": "kernel", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/o:redhat:enterprise_linux:7"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 7", "packageName": "kernel-rt", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "unaffected"}, {"cpes": ["cpe:/o:redhat:enterprise_linux:9"], "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9", "packageName": "kernel-rt", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "defaultStatus": "affected"}], "timeline": [{"lang": "en", "time": "2026-05-01T00:00:00.000Z", "value": "Reported to Red Hat."}, {"lang": "en", "time": "2026-05-01T00:00:00.000Z", "value": "Made public."}], "solutions": [{"lang": "en", "value": "RHSA-2026:24343: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux BaseOS EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0), Red Hat Enterprise Linux Real Time EUS (v. 10.0), Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0)"}, {"lang": "en", "value": "RHSA-2026:23329: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Real Time (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10)"}, {"lang": "en", "value": "RHSA-2026:22940: Red Hat Enterprise Linux AppStream E4S (v.9.2), Red Hat Enterprise Linux BaseOS E4S (v.9.2)"}, {"lang": "en", "value": "RHSA-2026:23237: Red Hat Enterprise Linux AppStream E4S (v.9.4), Red Hat Enterprise Linux BaseOS E4S (v.9.4), Red Hat Enterprise Linux Real Time E4S (v.9.4), Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4)"}, {"lang": "en", "value": "RHSA-2026:23224: Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat Enterprise Linux BaseOS EUS (v.9.6), Red Hat Enterprise Linux Real Time EUS (v.9.6), Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6)"}, {"lang": "en", "value": "RHSA-2026:21556: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9)"}, {"lang": "en", "value": "RHSA-2026:21706: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8)"}, {"lang": "en", "value": "RHSA-2026:21745: Red Hat Enterprise Linux NFV (v. 8), Red Hat Enterprise Linux RT (v. 8)"}, {"lang": "en", "value": "RHSA-2026:22900: Red Hat Enterprise Linux Real Time E4S (v.9.2), Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)"}], "x_adpType": "supplier", "datePublic": "2026-05-01T00:00:00.000Z", "references": [{"url": "https://access.redhat.com/security/cve/CVE-2026-31709", "tags": ["vdb-entry", "x_refsource_REDHAT"]}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2464476", "name": "RHBZ#2464476", "tags": ["issue-tracking", "x_refsource_REDHAT"]}, {"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31709.json", "tags": ["x_sadp-csaf-vex"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:24343", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:23329", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:22940", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:23237", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:23224", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:21556", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:21706", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:21745", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}, {"url": "https://access.redhat.com/errata/RHSA-2026:22900", "tags": ["vendor-advisory", "x_refsource_REDHAT"]}], "workarounds": [{"lang": "en", "value": "To mitigate this issue, if SMB client functionality is not required, the `cifs` kernel module can be blacklisted to prevent it from loading. This can be achieved by creating a modprobe configuration file.\n\n1. Create a file named `/etc/modprobe.d/disable-cifs.conf` with the following content:\n ```\n install cifs /bin/true\n blacklist cifs\n ```\n2. Regenerate the initramfs to ensure the change takes effect on boot:\n ```bash\n dracut -f -v\n ```\n or for systems using `mkinitrd`:\n ```bash\n mkinitrd -f /boot/initramfs-$(uname -r).img $(uname -r)\n ```\n3. A system reboot is required for the changes to take effect.\n\nWarning: Disabling the `cifs` module will prevent the system from mounting SMB/CIFS shares. Ensure this functionality is not critical before applying this mitigation.\n\nrefer: https://access.redhat.com/solutions/4117281"}], "x_generator": {"engine": "sadp-cli 1.0.0"}, "descriptions": [{"lang": "en", "value": "A flaw was found in the Linux kernel's Server Message Block (SMB) client, specifically within the cifsacl functionality. A malicious SMB server could provide a malformed Discretionary Access Control List (DACL) that claims to contain more Access Control Entries (ACEs) than are actually present. This insufficient validation allows the kernel to read or copy data beyond the intended memory boundaries, leading to memory corruption. This could potentially result in information disclosure or a denial of service."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-1288", "description": "Improper Validation of Consistency within Input"}]}], "providerMetadata": {"orgId": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "shortName": "redhat-SADP", "dateUpdated": "2026-07-15T01:08:58.337Z"}}, {"affected": [{"vendor": "Siemens", "product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem", "versions": [{"status": "affected", "version": "0", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}], "x_adpType": "supplier", "references": [{"url": "https://cert-portal.siemens.com/productcert/html/ssa-784472.html"}], "providerMetadata": {"orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-10-15T01:18:05.846Z"}}, {"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-31709", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T15:12:47.844968Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-125", "description": "CWE-125 Out-of-bounds Read"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T15:12:48.414Z"}}], "cna": {"title": "smb: client: validate the whole DACL before rewriting it in cifsacl", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 8.8, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"}, "scenarios": [{"lang": "en", "value": "AV:N - The vulnerable DACL is supplied by an SMB server over network SMB/CIFS ACL query responses and parsed by the Linux SMB client in kernel context. A malicious or compromised SMB server can deliver the crafted security descriptor over TCP.\nAC:L - After the client reaches the CIFS ACL path, the attacker controls the DACL offsets, sizes, ACE count, and ACE bytes in the server response. There is no race or condition outside attacker control needed to trigger the malformed ACE walk.\nPR:N - The attacker needs no privileges on the victim system; they only need to act as or control the SMB server that the client uses. Local chmod/chown permission checks apply to the victim-side process, not to the remote attacker.\nUI:R - Exploitation requires the victim system or an automated victim workflow to mount/use the SMB share and issue metadata operations such as stat, chmod, chown, or chgrp. The server cannot trigger this parser without a client request.\nS:U - The vulnerable component and the impacted resource are the same Linux kernel security authority on the SMB client. This is not a VM escape, IOMMU bypass, or cross-authority boundary violation.\nC:H - The malformed DACL can drive out-of-bounds reads while copying ACE/SID data, and rewritten ACL data can be sent back to the malicious server. Under the required high-severity tie-break rule, this is treated as high confidentiality impact.\nI:H - The chown/chgrp rewrite path can copy attacker-influenced ACEs into a newly allocated security descriptor beyond the size derived from the declared DACL, creating kernel heap memory corruption. Such corruption is potentially exploitable for arbitrary write or code execution.\nA:H - Malformed server-controlled ACL structures can drive out-of-bounds kernel memory access during ACL parsing or rewriting. Even without full exploitation, this can crash or oops the kernel."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "lessThan": "b8603d9ae6c9087662b098619996bc4a8064319d", "versionType": "git"}, {"status": "affected", "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "lessThan": "c2abdebf72000a64603ced84d36ccbd164f11391", "versionType": "git"}, {"status": "affected", "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "lessThan": "8e47d297e7cf9a6029a0d38e7b22faba7d7aaf12", "versionType": "git"}, {"status": "affected", "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "lessThan": "d92f3f0b22414e7515696a02224d0af55e3004a3", "versionType": "git"}, {"status": "affected", "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "lessThan": "ff0ca46b13b9ef6edbcd238a3b6caacfef8ba0e5", "versionType": "git"}, {"status": "affected", "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "lessThan": "b78db9bddc84136f6a0bb49e8883cf200dfb87a8", "versionType": "git"}, {"status": "affected", "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "lessThan": "0a8cf165566ba55a39fd0f4de172119dd646d39a", "versionType": "git"}], "programFiles": ["fs/smb/client/cifsacl.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.12"}, {"status": "unaffected", "version": "0", "lessThan": "5.12", "versionType": "semver"}, {"status": "unaffected", "version": "5.15.210", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.176", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.140", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.86", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.35", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.0.2", "versionType": "semver", "lessThanOrEqual": "7.0.*"}, {"status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["fs/smb/client/cifsacl.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/b8603d9ae6c9087662b098619996bc4a8064319d"}, {"url": "https://git.kernel.org/stable/c/c2abdebf72000a64603ced84d36ccbd164f11391"}, {"url": "https://git.kernel.org/stable/c/8e47d297e7cf9a6029a0d38e7b22faba7d7aaf12"}, {"url": "https://git.kernel.org/stable/c/d92f3f0b22414e7515696a02224d0af55e3004a3"}, {"url": "https://git.kernel.org/stable/c/ff0ca46b13b9ef6edbcd238a3b6caacfef8ba0e5"}, {"url": "https://git.kernel.org/stable/c/b78db9bddc84136f6a0bb49e8883cf200dfb87a8"}, {"url": "https://git.kernel.org/stable/c/0a8cf165566ba55a39fd0f4de172119dd646d39a"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: validate the whole DACL before rewriting it in cifsacl\n\nbuild_sec_desc() and id_mode_to_cifs_acl() derive a DACL pointer from a\nserver-supplied dacloffset and then use the incoming ACL to rebuild the\nchmod/chown security descriptor.\n\nThe original fix only checked that the struct smb_acl header fits before\nreading dacl_ptr->size or dacl_ptr->num_aces. That avoids the immediate\nheader-field OOB read, but the rewrite helpers still walk ACEs based on\npdacl->num_aces with no structural validation of the incoming DACL body.\n\nA malicious server can return a truncated DACL that still contains a\nheader, claims one or more ACEs, and then drive\nreplace_sids_and_copy_aces() or set_chmod_dacl() past the validated\nextent while they compare or copy attacker-controlled ACEs.\n\nFactor the DACL structural checks into validate_dacl(), extend them to\nvalidate each ACE against the DACL bounds, and use the shared validator\nbefore the chmod/chown rebuild paths. parse_dacl() reuses the same\nvalidator so the read-side parser and write-side rewrite paths agree on\nwhat constitutes a well-formed incoming DACL."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.15.210", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.176", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.140", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.86", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.35", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.0.2", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.1", "versionStartIncluding": "5.12"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:24:44.209Z"}}}, "cveMetadata": {"cveId": "CVE-2026-31709", "state": "PUBLISHED", "dateUpdated": "2026-10-19T19:06:06.980Z", "dateReserved": "2026-03-09T15:48:24.133Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-05-01T13:56:06.522Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/smb/client/cifsacl.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "b8603d9ae6c9087662b098619996bc4a8064319d", "status": "affected", "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "versionType": "git"}, {"lessThan": "c2abdebf72000a64603ced84d36ccbd164f11391", "status": "affected", "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "versionType": "git"}, {"lessThan": "8e47d297e7cf9a6029a0d38e7b22faba7d7aaf12", "status": "affected", "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "versionType": "git"}, {"lessThan": "d92f3f0b22414e7515696a02224d0af55e3004a3", "status": "affected", "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "versionType": "git"}, {"lessThan": "ff0ca46b13b9ef6edbcd238a3b6caacfef8ba0e5", "status": "affected", "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "versionType": "git"}, {"lessThan": "b78db9bddc84136f6a0bb49e8883cf200dfb87a8", "status": "affected", "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "versionType": "git"}, {"lessThan": "0a8cf165566ba55a39fd0f4de172119dd646d39a", "status": "affected", "version": "bc3e9dd9d104ca1b75644eab87b38ce8a924aef4", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/smb/client/cifsacl.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.12"}, {"lessThan": "5.12", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.210", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.176", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.140", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.86", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.35", "versionType": "semver"}, {"lessThanOrEqual": "7.0.*", "status": "unaffected", "version": "7.0.2", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"affectedData": [{"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:10.2"], "defaultStatus": "affected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 10", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:6.12.0-211.20.1.el10_2", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux_eus:10.0"], "defaultStatus": "affected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 10.0 Extended Update Support", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:6.12.0-55.77.1.el10_0", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:enterprise_linux:8::nfv"], "defaultStatus": "affected", "packageName": "kernel-rt", "product": "Red Hat Enterprise Linux 8", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:4.18.0-553.126.1.rt7.467.el8_10", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:8"], "defaultStatus": "affected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 8", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:4.18.0-553.126.1.el8_10", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:enterprise_linux:9", "cpe:/o:redhat:enterprise_linux:9"], "defaultStatus": "affected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 9", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:5.14.0-687.12.1.el9_8", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:rhel_e4s:9.2"], "defaultStatus": "affected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:5.14.0-284.174.1.el9_2", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:rhel_e4s:9.2::nfv"], "defaultStatus": "affected", "packageName": "kernel-rt", "product": "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:5.14.0-284.174.1.rt14.459.el9_2", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:rhel_e4s:9.4"], "defaultStatus": "affected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:5.14.0-427.129.1.el9_4", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/a:redhat:rhel_eus:9.6"], "defaultStatus": "affected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 9.6 Extended Update Support", "vendor": "Red Hat", "versions": [{"lessThan": "*", "status": "unaffected", "version": "0:5.14.0-570.119.1.el9_6", "versionType": "rpm"}]}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:6"], "defaultStatus": "unaffected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 6", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:7"], "defaultStatus": "unaffected", "packageName": "kernel", "product": "Red Hat Enterprise Linux 7", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:7"], "defaultStatus": "unaffected", "packageName": "kernel-rt", "product": "Red Hat Enterprise Linux 7", "vendor": "Red Hat"}, {"collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "cpes": ["cpe:/o:redhat:enterprise_linux:9"], "defaultStatus": "affected", "packageName": "kernel-rt", "product": "Red Hat Enterprise Linux 9", "vendor": "Red Hat"}], "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}, {"affectedData": [{"defaultStatus": "unknown", "product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem", "vendor": "Siemens", "versions": [{"lessThan": "*", "status": "affected", "version": "0", "versionType": "custom"}]}], "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "57E416E8-C706-4061-8BC1-7C61879FD612", "versionEndExcluding": "7.0.2", "versionStartIncluding": "5.12", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: validate the whole DACL before rewriting it in cifsacl\n\nbuild_sec_desc() and id_mode_to_cifs_acl() derive a DACL pointer from a\nserver-supplied dacloffset and then use the incoming ACL to rebuild the\nchmod/chown security descriptor.\n\nThe original fix only checked that the struct smb_acl header fits before\nreading dacl_ptr->size or dacl_ptr->num_aces. That avoids the immediate\nheader-field OOB read, but the rewrite helpers still walk ACEs based on\npdacl->num_aces with no structural validation of the incoming DACL body.\n\nA malicious server can return a truncated DACL that still contains a\nheader, claims one or more ACEs, and then drive\nreplace_sids_and_copy_aces() or set_chmod_dacl() past the validated\nextent while they compare or copy attacker-controlled ACEs.\n\nFactor the DACL structural checks into validate_dacl(), extend them to\nvalidate each ACE against the DACL bounds, and use the shared validator\nbefore the chmod/chown rebuild paths. parse_dacl() reuses the same\nvalidator so the read-side parser and write-side rewrite paths agree on\nwhat constitutes a well-formed incoming DACL."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nsmb: cliente: validar todo el DACL antes de reescribirlo en cifsacl\n\nbuild_sec_desc() e id_mode_to_cifs_acl() derivan un puntero DACL de un dacloffset proporcionado por el servidor y luego usan el ACL entrante para reconstruir el descriptor de seguridad chmod/chown.\n\nLa correcci\u00f3n original solo verificaba que el encabezado de la estructura smb_acl encajara antes de leer dacl_ptr -> size o dacl_ptr -> num_aces. Eso evita la lectura OOB inmediata del campo de encabezado, pero los ayudantes de reescritura a\u00fan recorren los ACE bas\u00e1ndose en pdacl -> num_aces sin validaci\u00f3n estructural del cuerpo del DACL entrante.\n\nUn servidor malicioso puede devolver un DACL truncado que a\u00fan contiene un encabezado, reclama uno o m\u00e1s ACE, y luego impulsa replace_sids_and_copy_aces() o set_chmod_dacl() m\u00e1s all\u00e1 del alcance validado mientras comparan o copian ACE controlados por el atacante.\n\nFactorizar las comprobaciones estructurales del DACL en validate_dacl(), extenderlas para validar cada ACE contra los l\u00edmites del DACL, y usar el validador compartido antes de las rutas de reconstrucci\u00f3n de chmod/chown. parse_dacl() reutiliza el mismo validador para que el analizador del lado de lectura y las rutas de reescritura del lado de escritura est\u00e9n de acuerdo sobre lo que constituye un DACL entrante bien formado."}], "id": "CVE-2026-31709", "lastModified": "2026-11-11T21:10:00.200", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-31709", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T15:12:47.844968Z", "version": "2.0.3"}}]}, "published": "2026-05-01T14:16:20.950", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/0a8cf165566ba55a39fd0f4de172119dd646d39a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8e47d297e7cf9a6029a0d38e7b22faba7d7aaf12"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/b78db9bddc84136f6a0bb49e8883cf200dfb87a8"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b8603d9ae6c9087662b098619996bc4a8064319d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c2abdebf72000a64603ced84d36ccbd164f11391"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d92f3f0b22414e7515696a02224d0af55e3004a3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ff0ca46b13b9ef6edbcd238a3b6caacfef8ba0e5"}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "url": "https://access.redhat.com/errata/RHSA-2026:21556"}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "url": "https://access.redhat.com/errata/RHSA-2026:21706"}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "url": "https://access.redhat.com/errata/RHSA-2026:21745"}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "url": "https://access.redhat.com/errata/RHSA-2026:22900"}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "url": "https://access.redhat.com/errata/RHSA-2026:22940"}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "url": "https://access.redhat.com/errata/RHSA-2026:23224"}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "url": "https://access.redhat.com/errata/RHSA-2026:23237"}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "url": "https://access.redhat.com/errata/RHSA-2026:23329"}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "url": "https://access.redhat.com/errata/RHSA-2026:24343"}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "url": "https://access.redhat.com/security/cve/CVE-2026-31709"}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2464476"}, {"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "url": "https://cert-portal.siemens.com/productcert/html/ssa-784472.html"}, {"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31709.json"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "nvd@nist.gov", "type": "Primary"}, {"description": [{"lang": "en", "value": "CWE-125"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}, {"description": [{"lang": "en", "value": "CWE-1288"}], "source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c", "type": "Secondary"}]}

{"bugzilla": {"description": "kernel: smb: client: validate the whole DACL before rewriting it in cifsacl", "id": "2464476", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2464476"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-1288", "details": ["A flaw was found in the Linux kernel's Server Message Block (SMB) client, specifically within the cifsacl functionality. A malicious SMB server could provide a malformed Discretionary Access Control List (DACL) that claims to contain more Access Control Entries (ACEs) than are actually present. This insufficient validation allows the kernel to read or copy data beyond the intended memory boundaries, leading to memory corruption. This could potentially result in information disclosure or a denial of service."], "name": "CVE-2026-31709", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-05-01T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-31709\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-31709\nhttps://lore.kernel.org/linux-cve-announce/2026050122-CVE-2026-31709-335b@gregkh/T"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[bc3e9dd9d104ca1b75644eab87b38ce8a924aef4,b78db9bddc84136f6a0bb49e8883cf200dfb87a8)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[bc3e9dd9d104ca1b75644eab87b38ce8a924aef4,0a8cf165566ba55a39fd0f4de172119dd646d39a)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "5.12"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,5.12)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.0.2,7.1.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.1-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-05-01T21:30:14.956999+00:00", "updated": "2026-10-23T08:45:16.397280+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}