CVE-2026-93801

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-93801", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-18T17:59:28.789Z", "datePublished": "2026-09-24T16:02:35.496Z", "dateUpdated": "2026-10-21T12:52:38.635Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:52:38.635Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb/client: zero-initialize stack-allocated cifs_open_info_data\n\nStack-allocated cifs_open_info_data may contain random data.\nThis can make some fields have wrong value if they are not set later."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - smb_set_file_info, cifs_query_mf_symlink, and __cifs_sfu_make_node allocate cifs_open_info_data on the stack and pass it to open/query_path_info. Those run only from local VFS setattr (cifs_setattr_nounix), O_TMPFILE (set_tmpfile_attr), sfu mknod/symlink, and MF-symlink lookup (check_mf_symlink), not from ksmbd or demux-thread PDU parsing.\nAC:H - smb_set_file_info calls cifs_query_path_info, which walks uninitialized wsl.eas, only when the SMB1 session lacks CAP_NT_SMBS, and that walk runs only after the query sets reparse_point from ATTR_REPARSE_POINT. A local attacker cannot strip CAP_NT_SMBS or force that DOS attribute on a typical NT/SMB2/SMB3 server.\nPR:L - cifs_setattr_nounix \u2192 cifs_set_file_info needs only inode ownership or directory write (utimensat, chmod clearing ATTR_READONLY, O_TMPFILE via set_tmpfile_attr). CIFS is not FS_USERNS_MOUNT, but using an already-mounted share does not require init-namespace CAP_SYS_ADMIN.\nUI:N - The attacker issues setattr, mknod/symlink, or lookup themselves on a share that is already mounted (fstab/autofs/CIFS home). No separate victim mount or open is required at exploit time.\nS:U - The stack out-of-bounds walk/write in cifs_query_path_info stays inside the client kernel CIFS code and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - With ATTR_REPARSE_POINT set, cifs_query_path_info walks data->wsl.eas using leftover next_entry_offset with no bound against SMB2_WSL_MAX_QUERY_EA_RESP_SIZE, an unbounded out-of-bounds read of kernel stack and adjacent memory.\nI:H - After that walk, CIFSSMBQAllEAs writes $LXMOD/$LXDEV through the wild ea pointer and the code stores next_entry_offset/ea_name_length/ea_value_length at that location, a stack out-of-bounds write.\nA:H - The while (next) loop over uninitialized next_entry_offset can spin without bound or dereference unmapped memory and oops, hanging or crashing the setattr path."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/client/link.c", "fs/smb/client/smb1ops.c", "fs/smb/client/smb2ops.c"], "versions": [{"version": "436cfdbc57d98808fce427d9a8d97691374989b3", "lessThan": "2c5db82778f560121efda9e052e2f19c2d807c1b", "status": "affected", "versionType": "git"}, {"version": "fc2f2011d3d84b56f536b4a25a4bb2fa1b13d520", "lessThan": "74ff47e6c4213fcfeba2de448d9cbda200507d22", "status": "affected", "versionType": "git"}, {"version": "057ac50638bcece64b3b436d3a61b70ed6c01a34", "lessThan": "22532dd88694ed20bdd47523ffa709f166ce776b", "status": "affected", "versionType": "git"}, {"version": "057ac50638bcece64b3b436d3a61b70ed6c01a34", "lessThan": "8fce4cf4369c766a3293a05419500cbfde72e60d", "status": "affected", "versionType": "git"}, {"version": "83d3bc866530a36a465b47cce4d2a9def2411960", "status": "affected", "versionType": "git"}, {"version": "6.6.113", "lessThan": "6.6.160", "status": "affected", "versionType": "semver"}, {"version": "6.12.54", "lessThan": "6.12.111", "status": "affected", "versionType": "semver"}, {"version": "6.17.4", "lessThan": "6.18", "status": "affected", "versionType": "semver"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/client/link.c", "fs/smb/client/smb1ops.c", "fs/smb/client/smb2ops.c"], "versions": [{"version": "6.18", "status": "affected"}, {"version": "0", "lessThan": "6.18", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.111", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.53", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "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": "6.6.113", "versionEndExcluding": "6.6.160"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12.54", "versionEndExcluding": "6.12.111"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18", "versionEndExcluding": "6.18.53"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18", "versionEndExcluding": "7.2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17.4"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/2c5db82778f560121efda9e052e2f19c2d807c1b"}, {"url": "https://git.kernel.org/stable/c/74ff47e6c4213fcfeba2de448d9cbda200507d22"}, {"url": "https://git.kernel.org/stable/c/22532dd88694ed20bdd47523ffa709f166ce776b"}, {"url": "https://git.kernel.org/stable/c/8fce4cf4369c766a3293a05419500cbfde72e60d"}], "title": "smb/client: zero-initialize stack-allocated cifs_open_info_data", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/smb/client/link.c", "fs/smb/client/smb1ops.c", "fs/smb/client/smb2ops.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "2c5db82778f560121efda9e052e2f19c2d807c1b", "status": "affected", "version": "436cfdbc57d98808fce427d9a8d97691374989b3", "versionType": "git"}, {"lessThan": "74ff47e6c4213fcfeba2de448d9cbda200507d22", "status": "affected", "version": "fc2f2011d3d84b56f536b4a25a4bb2fa1b13d520", "versionType": "git"}, {"lessThan": "22532dd88694ed20bdd47523ffa709f166ce776b", "status": "affected", "version": "057ac50638bcece64b3b436d3a61b70ed6c01a34", "versionType": "git"}, {"lessThan": "8fce4cf4369c766a3293a05419500cbfde72e60d", "status": "affected", "version": "057ac50638bcece64b3b436d3a61b70ed6c01a34", "versionType": "git"}, {"status": "affected", "version": "83d3bc866530a36a465b47cce4d2a9def2411960", "versionType": "git"}, {"lessThan": "6.6.160", "status": "affected", "version": "6.6.113", "versionType": "semver"}, {"lessThan": "6.12.111", "status": "affected", "version": "6.12.54", "versionType": "semver"}, {"lessThan": "6.18", "status": "affected", "version": "6.17.4", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/smb/client/link.c", "fs/smb/client/smb1ops.c", "fs/smb/client/smb2ops.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.18"}, {"lessThan": "6.18", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.160", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.111", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.53", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb/client: zero-initialize stack-allocated cifs_open_info_data\n\nStack-allocated cifs_open_info_data may contain random data.\nThis can make some fields have wrong value if they are not set later."}], "id": "CVE-2026-93801", "lastModified": "2026-10-21T13:21:08.140", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.0, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.0, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-24T17:17:13.017", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/22532dd88694ed20bdd47523ffa709f166ce776b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2c5db82778f560121efda9e052e2f19c2d807c1b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/74ff47e6c4213fcfeba2de448d9cbda200507d22"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8fce4cf4369c766a3293a05419500cbfde72e60d"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: smb/client: zero-initialize stack-allocated cifs_open_info_data", "id": "2540409", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2540409"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-908", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nsmb/client: zero-initialize stack-allocated cifs_open_info_data\nStack-allocated cifs_open_info_data may contain random data.\nThis can make some fields have wrong value if they are not set later.", "A flaw was found in the Linux kernel's SMB (Server Message Block) client. Certain file information structures allocated on the stack are not zero-initialized, leaving them containing random data when specific fields are not explicitly set. A local user performing file operations on a mounted SMB share could cause the kernel to process this uninitialized memory. This vulnerability can lead to a Denial of Service (DoS) via a system crash or result in unexpected kernel behavior."], "name": "CVE-2026-93801", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "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": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-09-24T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-93801\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-93801\nhttps://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93801.mbox"], "threat_severity": "Low"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,74ff47e6c4213fcfeba2de448d9cbda200507d22)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,22532dd88694ed20bdd47523ffa709f166ce776b)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,8fce4cf4369c766a3293a05419500cbfde72e60d)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,6.12.111)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,6.18.53)"}}], "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": "unaffected", "versions": {"scheme": "generic", "value": "[6.12.111,6.12.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.18.53,6.18.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,*]"}}], "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": "2026-09-24T20:45:07.553499+00:00", "updated": "2026-10-01T16:45:09.991109+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-665", "CWE-908"]}