{"id":"CVE-2026-64138","title":"ksmbd: validate SID in parent security descriptor during ACL inheritance","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: validate SID in parent security descriptor during ACL inheritance\n\nIntroduce smb_validate_ntsd_sid() helper to safely validate Owner SID\nand Group SID inside the…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 8efbea0253b7fa2d1960cab0fed36544ca0b41ab","Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < f0e5c9c663badc9982e6941322eef1cb17de0f11","Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 18d8db24b0a5b7be4829238dd4022236df02d421","Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 1c9d0646a9959752f11ca1080dc1ff26bd1756cb","Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 69f030cf95488ae1186c72ac8c66fd279664ea7f","Linux 5.15"],"published":"2026-07-19","updated":"2026-10-21","sourceUpdated":"2026-10-21T12:43:05.753Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64138","references":[{"url":"https://git.kernel.org/stable/c/8efbea0253b7fa2d1960cab0fed36544ca0b41ab"},{"url":"https://git.kernel.org/stable/c/f0e5c9c663badc9982e6941322eef1cb17de0f11"},{"url":"https://git.kernel.org/stable/c/18d8db24b0a5b7be4829238dd4022236df02d421"},{"url":"https://git.kernel.org/stable/c/1c9d0646a9959752f11ca1080dc1ff26bd1756cb"},{"url":"https://git.kernel.org/stable/c/69f030cf95488ae1186c72ac8c66fd279664ea7f"}],"tags":["cve.org"],"epss":0.00415,"epssPercentile":0.34433,"ingestedAt":"2026-10-21T12:48:53.610Z","slug":"CVE-2026-64138","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: validate SID in parent security descriptor during ACL inheritance\n\nIntroduce smb_validate_ntsd_sid() helper to safely validate Owner SID\nand Group SID inside the NT Security Descriptor (smb_ntsd) retrieved\nfrom the parent directory.\n\n## Affected\n\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 8efbea0253b7fa2d1960cab0fed36544ca0b41ab`\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < f0e5c9c663badc9982e6941322eef1cb17de0f11`\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 18d8db24b0a5b7be4829238dd4022236df02d421`\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 1c9d0646a9959752f11ca1080dc1ff26bd1756cb`\n- `Linux >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 69f030cf95488ae1186c72ac8c66fd279664ea7f`\n- `Linux 5.15`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}