CVE-2026-31611

{"id": "CVE-2026-31611", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.6, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}, "impactScore": 4.7, "exploitabilityScore": 3.9}]}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "cf2148b880fb7c0fcd727202dbc4fd5d6998b9c2", "versionType": "git"}, {"status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "b5b5d5936a50497fb151c0b122899a6894721c2b", "versionType": "git"}, {"status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "08f9e6d899b5c834bbcc239eae1bed58d9b15d2c", "versionType": "git"}, {"status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "d2454f4a002d08560a60f214f392e6491cf11560", "versionType": "git"}, {"status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "46bbcd3ebfb3549c8da1838fc4493e79bd3241e7", "versionType": "git"}, {"status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "9401f86a224f37b50e6a3ccf1d46a70d5ef8af0a", "versionType": "git"}, {"status": "affected", "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "53370cf9090777774e07fd9a8ebce67c6cc333ab", "versionType": "git"}], "programFiles": ["fs/smb/server/smbacl.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.15"}, {"status": "unaffected", "version": "0", "lessThan": "5.15", "versionType": "semver"}, {"status": "unaffected", "version": "6.1.175", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.136", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.83", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.24", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "6.19.14", "versionType": "semver", "lessThanOrEqual": "6.19.*"}, {"status": "unaffected", "version": "7.0.1", "versionType": "semver", "lessThanOrEqual": "7.0.*"}, {"status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["fs/smb/server/smbacl.c"], "defaultStatus": "affected"}]}, {"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "affectedData": [{"vendor": "Siemens", "product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem", "versions": [{"status": "affected", "version": "0", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}]}], "published": "2026-04-24T15:16:40.360", "references": [{"url": "https://git.kernel.org/stable/c/08f9e6d899b5c834bbcc239eae1bed58d9b15d2c", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/46bbcd3ebfb3549c8da1838fc4493e79bd3241e7", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/53370cf9090777774e07fd9a8ebce67c6cc333ab", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/9401f86a224f37b50e6a3ccf1d46a70d5ef8af0a", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b5b5d5936a50497fb151c0b122899a6894721c2b", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/cf2148b880fb7c0fcd727202dbc4fd5d6998b9c2", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/d2454f4a002d08560a60f214f392e6491cf11560", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://cert-portal.siemens.com/productcert/html/ssa-784472.html", "source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: require 3 sub-authorities before reading sub_auth[2]\n\nparse_dacl() compares each ACE SID against sid_unix_NFS_mode and on\nmatch reads sid.sub_auth[2] as the file mode. If sid_unix_NFS_mode is\nthe prefix S-1-5-88-3 with num_subauth = 2 then compare_sids() compares\nonly min(num_subauth, 2) sub-authorities so a client SID with\nnum_subauth = 2 and sub_auth = {88, 3} will match.\n\nIf num_subauth = 2 and the ACE is placed at the very end of the security\ndescriptor, sub_auth[2] will be 4 bytes past end_of_acl. The\nout-of-band bytes will then be masked to the low 9 bits and applied as\nthe file's POSIX mode, probably not something that is good to have\nhappen.\n\nFix this up by forcing the SID to actually carry a third sub-authority\nbefore reading it at all."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nksmbd: requiere 3 subautoridades antes de leer sub_auth[2]\n\nparse_dacl() compara cada SID de ACE contra sid_unix_NFS_mode y, en caso de coincidencia, lee sid.sub_auth[2] como el modo de archivo. Si sid_unix_NFS_mode es el prefijo S-1-5-88-3 con num_subauth = 2, entonces compare_sids() compara solo min(num_subauth, 2) subautoridades, por lo que un SID de cliente con num_subauth = 2 y sub_auth = {88, 3} coincidir\u00e1.\n\nSi num_subauth = 2 y el ACE se coloca al final del descriptor de seguridad, sub_auth[2] estar\u00e1 4 bytes m\u00e1s all\u00e1 de end_of_acl. Los bytes fuera de banda se enmascarar\u00e1n entonces a los 9 bits bajos y se aplicar\u00e1n como el modo POSIX del archivo, probablemente no sea algo bueno que suceda.\n\nSolucione esto forzando al SID a llevar realmente una tercera subautoridad antes de leerlo en absoluto."}], "lastModified": "2026-11-11T23:10:00.263", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B1ABA9F0-A5C4-4CBE-92EC-33CA7D4F7634", "versionEndExcluding": "6.6.136", "versionStartIncluding": "5.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "7F0AE5B5-23AC-4DCC-B37A-51CA1DAE7BA8", "versionEndExcluding": "6.12.83", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8126B8B8-6D0B-4443-86C1-672AEE893555", "versionEndExcluding": "6.18.24", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D6A8A074-BBF4-4803-ABED-519A839435BB", "versionEndExcluding": "6.19.14", "versionStartIncluding": "6.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "9B5888AB-7403-4335-89E4-21CC0B48366A", "versionEndExcluding": "7.0.1", "versionStartIncluding": "7.0"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}