{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-31610", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.122Z", "datePublished": "2026-04-24T14:42:31.471Z", "dateUpdated": "2026-07-24T14:33:31.688Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-07-24T14:33:31.688Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix mechToken leak when SPNEGO decode fails after token alloc\n\nThe kernel ASN.1 BER decoder calls action callbacks incrementally as it\nwalks the input. When ksmbd_decode_negTokenInit() reaches the mechToken\n[2] OCTET STRING element, ksmbd_neg_token_alloc() allocates\nconn->mechToken immediately via kmemdup_nul(). If a later element in\nthe same blob is malformed, then the decoder will return nonzero after\nthe allocation is already live. This could happen if mechListMIC [3]\noverrunse the enclosing SEQUENCE.\n\ndecode_negotiation_token() then sets conn->use_spnego = false because\nboth the negTokenInit and negTokenTarg grammars failed. The cleanup at\nthe bottom of smb2_sess_setup() is gated on use_spnego:\n\n\tif (conn->use_spnego && conn->mechToken) {\n\t\tkfree(conn->mechToken);\n\t\tconn->mechToken = NULL;\n\t}\n\nso the kfree is skipped, causing the mechToken to never be freed.\n\nThis codepath is reachable pre-authentication, so untrusted clients can\ncause slow memory leaks on a server without even being properly\nauthenticated.\n\nFix this up by not checking check for use_spnego, as it's not required,\nso the memory will always be properly freed. At the same time, always\nfree the memory in ksmbd_conn_free() incase some other failure path\nforgot to free it." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/connection.c", "fs/smb/server/smb2pdu.c" ], "versions": [ { "version": "fad4161b5cd01a24202234976ebbb133f7adc0b5", "lessThan": "ae9cdb29efed20ffdee9ff3b0bb72fb369c353da", "status": "affected", "versionType": "git" }, { "version": "fad4161b5cd01a24202234976ebbb133f7adc0b5", "lessThan": "bd4a7fb04f06f419b0e93d8b52fe32067eb312d1", "status": "affected", "versionType": "git" }, { "version": "fad4161b5cd01a24202234976ebbb133f7adc0b5", "lessThan": "745a535461bbb90a56d9357573c9f97a5c12abe1", "status": "affected", "versionType": "git" }, { "version": "fad4161b5cd01a24202234976ebbb133f7adc0b5", "lessThan": "dd577cb55588ec3fbc66af3621280306601c4192", "status": "affected", "versionType": "git" }, { "version": "fad4161b5cd01a24202234976ebbb133f7adc0b5", "lessThan": "dd53414e301beb915fe672dc4c4a51bafb917604", "status": "affected", "versionType": "git" }, { "version": "fad4161b5cd01a24202234976ebbb133f7adc0b5", "lessThan": "269c800a7a7e363459291885b35f7bc72e231ed6", "status": "affected", "versionType": "git" }, { "version": "fad4161b5cd01a24202234976ebbb133f7adc0b5", "lessThan": "6c8c44e6553b9f072f62d9875e567766eb293162", "status": "affected", "versionType": "git" }, { "version": "fad4161b5cd01a24202234976ebbb133f7adc0b5", "lessThan": "ad0057fb91218914d6c98268718ceb9d59b388e1", "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/connection.c", "fs/smb/server/smb2pdu.c" ], "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.212", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.136", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.83", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.24", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.14", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.1", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "5.15.212" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.6.136" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.12.83" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.18.24" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.19.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.0.1" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ae9cdb29efed20ffdee9ff3b0bb72fb369c353da" }, { "url": "https://git.kernel.org/stable/c/bd4a7fb04f06f419b0e93d8b52fe32067eb312d1" }, { "url": "https://git.kernel.org/stable/c/745a535461bbb90a56d9357573c9f97a5c12abe1" }, { "url": "https://git.kernel.org/stable/c/dd577cb55588ec3fbc66af3621280306601c4192" }, { "url": "https://git.kernel.org/stable/c/dd53414e301beb915fe672dc4c4a51bafb917604" }, { "url": "https://git.kernel.org/stable/c/269c800a7a7e363459291885b35f7bc72e231ed6" }, { "url": "https://git.kernel.org/stable/c/6c8c44e6553b9f072f62d9875e567766eb293162" }, { "url": "https://git.kernel.org/stable/c/ad0057fb91218914d6c98268718ceb9d59b388e1" } ], "title": "ksmbd: fix mechToken leak when SPNEGO decode fails after token alloc", "x_generator": 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