CVE-2026-72382

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-72382", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.923Z", "datePublished": "2026-08-15T05:56:14.103Z", "dateUpdated": "2026-10-30T12:29:13.532Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-30T12:29:13.532Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: reject undersized DACLs before parsing ACEs\n\nparse_dacl() limits the attacker-controlled ACE count by comparing it\nwith the number of minimal ACEs that fit in the DACL size. The DACL size\nfield is 16 bits, but the expression subtracts sizeof(struct smb_acl).\nBecause sizeof() is unsigned, a DACL size smaller than the ACL header\nunderflows to a large size_t.\n\nA malicious client can reach this with:\n\nSMB2_SET_INFO (InfoType=SMB2_O_INFO_SECURITY)\n -> smb2_set_info_sec()\n -> set_info_sec()\n -> parse_sec_desc()\n -> parse_dacl()\n -> init_acl_state(..., 0xffff)\n -> init_acl_state(..., 0xffff)\n -> kmalloc_objs(..., 0xffff)\n\nThus a malformed security descriptor can make num_aces pass the guard\nand drive large temporary ACL state and pointer-array allocations.\n\nReject DACLs smaller than struct smb_acl before doing the subtraction,\nso the ACE count check cannot be bypassed by the underflow."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - The flaw is reached through ksmbd's in-kernel SMB2 server on TCP/445 via SMB2_SET_INFO (InfoType=SMB2_O_INFO_SECURITY) or SMB2 CREATE with an SD buffer, both handled from remote network input.\nAC:L - An attacker reliably triggers the bug by sending a crafted security descriptor with DACL size below 8 bytes and a large num_aces (e.g. 0xFFFF), bypassing the underflowed ACE-count check without special timing or victim state.\nPR:L - Exploitation requires an authenticated SMB session, a writable tree connect, an open file handle (or CREATE with SD buffer), and FILE_WRITE_DAC or FILE_WRITE_OWNER access on that object.\nUI:N - No victim interaction is required beyond the attacker sending malicious SMB2 protocol requests to an exposed ksmbd server.\nS:U - Impact is confined to kernel memory exhaustion and ksmbd availability within the same host security authority; it does not cross VM, container, or IOMMU boundaries.\nC:H - The unsigned underflow bypasses DACL bounds validation, letting attacker-controlled num_aces drive multi-megabyte kernel heap allocations and parse attacker-supplied ACE data from malformed security descriptors.\nI:H - Attacker-controlled allocation sizing from bypassed validation creates large heap manipulation primitives in kernel context, consistent with similar ksmbd DACL integer-validation flaws scored at high integrity impact.\nA:H - Each malicious request forces roughly 2.5 MB of kernel allocations; repeated or concurrent SMB2_SET_INFO calls can exhaust memory, trigger OOM/page-allocator failures, and deny service to ksmbd and the host."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/smb/server/smbacl.c"], "versions": [{"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "8dc949061e35427433feac3ebe5ec089f2aa857e", "status": "affected", "versionType": "git"}, {"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "16fb65ec15fe7c90f50a2115854bfd9a032d4023", "status": "affected", "versionType": "git"}, {"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "282847c0cf22f2e961155ac8e42f6eeab7e16049", "status": "affected", "versionType": "git"}, {"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "d020e7f27bf65eecd3805404702f716b2b6d9e73", "status": "affected", "versionType": "git"}, {"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "15a9e9b8f7f5d7f380ae54c6f5bcbc0bdcb0f3cd", "status": "affected", "versionType": "git"}, {"version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "60908f7ebcd9b6cde74ad5711fab0f49c7970949", "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/server/smbacl.c"], "versions": [{"version": "5.15", "status": "affected"}, {"version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.191", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.5", "lessThanOrEqual": "7.1.*", "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": "5.15", "versionEndExcluding": "6.1.191"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.6.145"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.12.97"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.18.40"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.1.5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/8dc949061e35427433feac3ebe5ec089f2aa857e"}, {"url": "https://git.kernel.org/stable/c/16fb65ec15fe7c90f50a2115854bfd9a032d4023"}, {"url": "https://git.kernel.org/stable/c/282847c0cf22f2e961155ac8e42f6eeab7e16049"}, {"url": "https://git.kernel.org/stable/c/d020e7f27bf65eecd3805404702f716b2b6d9e73"}, {"url": "https://git.kernel.org/stable/c/15a9e9b8f7f5d7f380ae54c6f5bcbc0bdcb0f3cd"}, {"url": "https://git.kernel.org/stable/c/60908f7ebcd9b6cde74ad5711fab0f49c7970949"}], "title": "ksmbd: reject undersized DACLs before parsing ACEs", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/smb/server/smbacl.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "8dc949061e35427433feac3ebe5ec089f2aa857e", "status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "versionType": "git"}, {"lessThan": "16fb65ec15fe7c90f50a2115854bfd9a032d4023", "status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "versionType": "git"}, {"lessThan": "282847c0cf22f2e961155ac8e42f6eeab7e16049", "status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "versionType": "git"}, {"lessThan": "d020e7f27bf65eecd3805404702f716b2b6d9e73", "status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "versionType": "git"}, {"lessThan": "15a9e9b8f7f5d7f380ae54c6f5bcbc0bdcb0f3cd", "status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "versionType": "git"}, {"lessThan": "60908f7ebcd9b6cde74ad5711fab0f49c7970949", "status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/smb/server/smbacl.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.15"}, {"lessThan": "5.15", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.191", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.145", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.97", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.40", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.5", "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\nksmbd: reject undersized DACLs before parsing ACEs\n\nparse_dacl() limits the attacker-controlled ACE count by comparing it\nwith the number of minimal ACEs that fit in the DACL size. The DACL size\nfield is 16 bits, but the expression subtracts sizeof(struct smb_acl).\nBecause sizeof() is unsigned, a DACL size smaller than the ACL header\nunderflows to a large size_t.\n\nA malicious client can reach this with:\n\nSMB2_SET_INFO (InfoType=SMB2_O_INFO_SECURITY)\n -> smb2_set_info_sec()\n -> set_info_sec()\n -> parse_sec_desc()\n -> parse_dacl()\n -> init_acl_state(..., 0xffff)\n -> init_acl_state(..., 0xffff)\n -> kmalloc_objs(..., 0xffff)\n\nThus a malformed security descriptor can make num_aces pass the guard\nand drive large temporary ACL state and pointer-array allocations.\n\nReject DACLs smaller than struct smb_acl before doing the subtraction,\nso the ACE count check cannot be bypassed by the underflow."}], "id": "CVE-2026-72382", "lastModified": "2026-10-30T13:19:50.623", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/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"}]}, "published": "2026-08-15T06:22:11.707", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/15a9e9b8f7f5d7f380ae54c6f5bcbc0bdcb0f3cd"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/16fb65ec15fe7c90f50a2115854bfd9a032d4023"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/282847c0cf22f2e961155ac8e42f6eeab7e16049"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/60908f7ebcd9b6cde74ad5711fab0f49c7970949"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8dc949061e35427433feac3ebe5ec089f2aa857e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d020e7f27bf65eecd3805404702f716b2b6d9e73"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: ksmbd: reject undersized DACLs before parsing ACEs", "id": "2516420", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2516420"}, "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-131", "details": ["A flaw was found in ksmbd in the Linux kernel. A remote attacker, by sending a specially crafted security descriptor with an undersized Discretionary Access Control List (DACL) during an SMB2_SET_INFO operation, can trigger an integer underflow. This underflow leads to excessive memory allocations for Access Control Entries (ACEs), potentially causing a Denial of Service (DoS) on the system."], "name": "CVE-2026-72382", "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": "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": "Not affected", "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"}], "public_date": "2026-08-15T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-72382\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-72382\nhttps://lore.kernel.org/linux-cve-announce/2026081518-CVE-2026-72382-aa5f@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9,16fb65ec15fe7c90f50a2115854bfd9a032d4023)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9,282847c0cf22f2e961155ac8e42f6eeab7e16049)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9,d020e7f27bf65eecd3805404702f716b2b6d9e73)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9,15a9e9b8f7f5d7f380ae54c6f5bcbc0bdcb0f3cd)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9,60908f7ebcd9b6cde74ad5711fab0f49c7970949)"}}], "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": "5.15"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,5.15)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.145,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.97,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.40,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.5,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc2,*]"}}], "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": "2026-08-15T18:30:12.330845+00:00", "updated": "2026-08-18T19:30:04.220228+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}