{"id":"CVE-2026-31613","revision":null,"records":[{"revision":"24d7841d3a404c329faacb641d70b7ac","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-31613","aliases":[],"title":"smb: client: fix OOB reads parsing symlink error response","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix OOB reads parsing symlink error response\n\nWhen a CREATE returns STATUS_STOPPED_ON_SYMLINK, smb2_check_message()\nreturns success without any length validation, leaving the symlink\nparsers as the only defense against an untrusted server.\n\nsymlink_data() walks SMB 3.1.1 error contexts with the loop test \"p <\nend\", but reads p->ErrorId at offset 4 and p->ErrorDataLength at offset\n0.  When the server-controlled ErrorDataLength advances p to within 1-7\nbytes of end, the next iteration will read past it.  When the matching\ncontext is found, sym->SymLinkErrorTag is read at offset 4 from\np->ErrorContextData with no check that the symlink header itself fits.\n\nsmb2_parse_symlink_response() then bounds-checks the substitute name\nusing SMB2_SYMLINK_STRUCT_SIZE as the offset of PathBuffer from\niov_base.  That value is computed as sizeof(smb2_err_rsp) +\nsizeof(smb2_symlink_err_rsp), which is correct only when\nErrorContextCount == 0.\n\nWith at least one error context the symlink data sits 8 bytes deeper,\nand each skipped non-matching context shifts it further by 8 +\nALIGN(ErrorDataLength, 8).  The check is too short, allowing the\nsubstitute name read to run past iov_len.  The out-of-bound heap bytes\nare UTF-16-decoded into the symlink target and returned to userspace via\nreadlink(2).\n\nFix this all up by making the loops test require the full context header\nto fit, rejecting sym if its header runs past end, and bound the\nsubstitute name against the actual position of sym->PathBuffer rather\nthan a fixed offset.\n\nBecause sub_offs and sub_len are 16bits, the pointer math will not\noverflow here with the new greater-than.","state":0,"publishedAt":"2026-04-24T14:42:33.453+00:00","modifiedAt":"2026-10-19T18:56:00.442+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/client/smb2file.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"76894f3e2f71177747b8b4763fb180e800279585\",\n                            \"lessThan\": \"043834e72337ee7b4e9685859888623ba1504ac7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"76894f3e2f71177747b8b4763fb180e800279585\",\n                            \"lessThan\": \"d65a64755a3df68a2fd19d2a81395e9f723aca23\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"76894f3e2f71177747b8b4763fb180e800279585\",\n                            \"lessThan\": \"20ac98f0eb6047edb73c9a27af782bdde08b3757\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"76894f3e2f71177747b8b4763fb180e800279585\",\n                            \"lessThan\": \"e0dd90d14cbbf318157ea8e3fb62ee68a28655ed\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"76894f3e2f71177747b8b4763fb180e800279585\",\n                            \"lessThan\": \"781902e069f4ecb6c3b83502f181972c1446110a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"76894f3e2f71177747b8b4763fb180e800279585\",\n                            \"lessThan\": \"a66ef2e7ed837325c5600f8617d5ee0a0a149fdd\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"76894f3e2f71177747b8b4763fb180e800279585\",\n                            \"lessThan\": \"3df690bba28edec865cf7190be10708ad0ddd67e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"2d046892a493d9760c35fdaefc3017f27f91b621\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"6.0.16\",\n                            \"lessThan\": \"6.1\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\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/client/smb2file.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.1\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.1\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.175\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.141\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.91\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.24\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.19.14\",\n                            \"lessThanOrEqual\": \"6.19.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0.1\",\n                            \"lessThanOrEqual\": \"7.0.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1\",\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:N/UI:R/S:U/C:H/I:N/A:H","score":8.1,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/043834e72337ee7b4e9685859888623ba1504ac7","https://git.kernel.org/stable/c/d65a64755a3df68a2fd19d2a81395e9f723aca23","https://git.kernel.org/stable/c/20ac98f0eb6047edb73c9a27af782bdde08b3757","https://git.kernel.org/stable/c/e0dd90d14cbbf318157ea8e3fb62ee68a28655ed","https://git.kernel.org/stable/c/781902e069f4ecb6c3b83502f181972c1446110a","https://git.kernel.org/stable/c/a66ef2e7ed837325c5600f8617d5ee0a0a149fdd","https://git.kernel.org/stable/c/3df690bba28edec865cf7190be10708ad0ddd67e"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-31613","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-31613","identifiers":["CVE-2026-31613"]},"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-45d47722bca14f09ac26662adb699591","complete":true,"records":13654,"lastAttemptAt":"2026-11-08T21:02:36.7086981+00:00","lastSuccessAt":"2026-11-08T20:47:46.939+00:00","error":null,"lastVerifiedAt":"2026-11-08T20:47:46.939+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":"2026-11-08T21:02:31.8931850+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-08T21:02:31.893185+00:00","lastSuccessAt":"2026-11-08T21:02:32.3894193+00:00","error":null,"lastVerifiedAt":"2026-11-08T21:02:32.38942+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-ddc095a411c54633beb68aaff30b70cb","complete":true,"records":13666,"lastAttemptAt":"2026-11-08T21:02:34.4952279+00:00","lastSuccessAt":"2026-11-08T21:02:34.481+00:00","error":null,"lastVerifiedAt":"2026-11-08T21:02:34.481+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":"2026-11-08T21:02:31.7841816+00:00","lastSuccessAt":"2026-11-08T11:07:07.068788+00:00","error":null,"lastVerifiedAt":"2026-11-08T21:02:31.7841816+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":"2026-11-08T21:02:31.5325642+00:00","lastSuccessAt":"2026-11-06T19:03:17.0399903+00:00","error":null,"lastVerifiedAt":"2026-11-08T21:02:31.5325642+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":"2026-11-08T21:02:31.8040207+00:00","lastSuccessAt":"2026-11-08T11:07:12.1927025+00:00","error":null,"lastVerifiedAt":"2026-11-08T21:02:31.8040207+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":"2026-11-08T21:02:31.6506398+00:00","lastSuccessAt":"2026-11-08T11:06:56.2918717+00:00","error":null,"lastVerifiedAt":"2026-11-08T21:02:31.6506398+00:00","snapshotPublishedAt":"2026-11-08T11:02:50+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}