{"id":"CVE-2026-68100","revision":null,"records":[{"revision":"576cb47581ea4ccc99c27c76894463f7","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-68100","aliases":[],"title":"ksmbd: validate num_subauth when copying ACE in set_ntacl_dacl","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: validate num_subauth when copying ACE in set_ntacl_dacl\n\nset_ntacl_dacl() copies each ACE from the attacker-controlled stored\nsecurity descriptor verbatim into the response DACL without checking\nsid.num_subauth. The ACE bytes (including an unchecked num_subauth)\noriginate from an authenticated SMB2_SET_INFO(SecInfo=DACL) that is\nstored raw via ksmbd_vfs_set_sd_xattr(); parse_dacl() rejects a bad ACE\nwith `break` rather than an error, so parse_sec_desc() still returns\nsuccess and the malformed SD reaches the xattr intact.\n\nOn a subsequent SMB2_QUERY_INFO(SecInfo=DACL) for an inode carrying a\nPOSIX access ACL, build_sec_desc() -> set_ntacl_dacl() ->\nset_posix_acl_entries_dacl() walks the copied ACEs and reads\n\n ntace->sid.sub_auth[ntace->sid.num_subauth - 1]\n\nwith num_subauth taken straight from the stored SD. Since sub_auth[]\nis fixed at SID_MAX_SUB_AUTHORITIES (15), a crafted num_subauth (e.g.\n255) drives an out-of-bounds heap read of ~1 KB with an offset fully\ncontrolled by an authenticated client.\n\nThe sibling functions already gate this field:\n parse_dacl() -- num_subauth == 0 || > SID_MAX_SUB_AUTHORITIES\n parse_sid() -- num_subauth > SID_MAX_SUB_AUTHORITIES\n smb_copy_sid() -- min_t(u8, num_subauth, SID_MAX_SUB_AUTHORITIES)\nset_ntacl_dacl() is the lone inconsistent path that omits the check.\n\nAdd the same num_subauth validation in set_ntacl_dacl() before copying\nthe ACE, matching the gate already enforced by parse_dacl().","state":0,"publishedAt":"2026-08-10T11:58:15.233+00:00","modifiedAt":"2026-10-19T20:58:50.348+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"fs/smb/server/smbacl.c\"\n ],\n \"versions\": [\n {\n \"version\": \"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9\",\n \"lessThan\": \"26cb845e22a00c85bf566337417fa33492395f10\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9\",\n \"lessThan\": \"e31fada5143784bc05c7ae44c79eed9b7a2e147e\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9\",\n \"lessThan\": \"fb3dc8e6da46a1ccad1956cda57de29d9b3033e0\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9\",\n \"lessThan\": \"b6d3cc6a524416dfdb2b47e4bba2e7e20011d056\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9\",\n \"lessThan\": \"5acbd3012fd4a7ccfebd91ea6f784120084eb897\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9\",\n \"lessThan\": \"47f0b34f6bc98ed85bfdc293e8f3e432ec24958d\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"fs/smb/server/smbacl.c\"\n ],\n \"versions\": [\n {\n \"version\": \"5.15\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"5.15\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.184\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.148\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.101\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.42\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.1.6\",\n \"lessThanOrEqual\": \"7.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.2\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","score":8.1,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/26cb845e22a00c85bf566337417fa33492395f10","https://git.kernel.org/stable/c/e31fada5143784bc05c7ae44c79eed9b7a2e147e","https://git.kernel.org/stable/c/fb3dc8e6da46a1ccad1956cda57de29d9b3033e0","https://git.kernel.org/stable/c/b6d3cc6a524416dfdb2b47e4bba2e7e20011d056","https://git.kernel.org/stable/c/5acbd3012fd4a7ccfebd91ea6f784120084eb897","https://git.kernel.org/stable/c/47f0b34f6bc98ed85bfdc293e8f3e432ec24958d"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-68100","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-68100","identifiers":["CVE-2026-68100"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. 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Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-3c4bbd4ca5ed46108ac75e394fa48ace","complete":true,"records":13654,"lastAttemptAt":"2026-11-08T16:11:35.9510843+00:00","lastSuccessAt":"2026-11-08T16:11:35.947+00:00","error":null,"lastVerifiedAt":"2026-11-08T16:11:35.947+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13706,"expectedIdentifiers":13706,"failedIdentifiers":0},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-08T16:11:32.8669692+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-08T16:11:32.8669692+00:00","lastSuccessAt":"2026-11-08T16:11:33.0716184+00:00","error":null,"lastVerifiedAt":"2026-11-08T16:11:33.0716198+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-7f3b9e580ebe475bb44f224af7ef38ba","complete":true,"records":13666,"lastAttemptAt":"2026-11-08T16:11:35.0811636+00:00","lastSuccessAt":"2026-11-08T16:11:35.077+00:00","error":null,"lastVerifiedAt":"2026-11-08T16:11:35.077+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13706,"expectedIdentifiers":13706,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-980593e6977a6d1b4fb1eed5a1ffe88a468736f89f0a06f710924ad59132c023","complete":true,"records":9914,"lastAttemptAt":"2026-11-08T16:11:32.7092062+00:00","lastSuccessAt":"2026-11-08T11:07:07.068788+00:00","error":null,"lastVerifiedAt":"2026-11-08T16:11:32.7092062+00:00","snapshotPublishedAt":"2026-11-08T11:02:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-fde804134ecdda0ddd5ff5c26ee1fff5a6fa659311f7ef2e51c6ad54964db0e2","complete":true,"records":1971,"lastAttemptAt":"2026-11-08T16:11:32.0361288+00:00","lastSuccessAt":"2026-11-06T19:03:17.0399903+00:00","error":null,"lastVerifiedAt":"2026-11-08T16:11:32.0361288+00:00","snapshotPublishedAt":"2026-11-06T18:17:57+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-964c14035e6f0f6478b2870fad6a7ef9f6045876d4a12af2c2e514521e54b6af","complete":true,"records":3055,"lastAttemptAt":"2026-11-08T16:11:32.8190262+00:00","lastSuccessAt":"2026-11-08T11:07:12.1927025+00:00","error":null,"lastVerifiedAt":"2026-11-08T16:11:32.8190262+00:00","snapshotPublishedAt":"2026-11-08T11:02:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-f8647d7ba64b1ba0dfdc7130944766d5b36d5b77d18fff0c79e651a4cff3c2b9","complete":true,"records":231293,"lastAttemptAt":"2026-11-08T16:11:32.2222906+00:00","lastSuccessAt":"2026-11-08T11:06:56.2918717+00:00","error":null,"lastVerifiedAt":"2026-11-08T16:11:32.2222906+00:00","snapshotPublishedAt":"2026-11-08T11:02:50+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}