{"api_version":"1","generated_at":"2026-04-23T11:10:53+00:00","cve":"CVE-2026-31476","urls":{"html":"https://cve.report/CVE-2026-31476","api":"https://cve.report/api/cve/CVE-2026-31476.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-31476","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-31476"},"summary":{"title":"ksmbd: do not expire session on binding failure","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: do not expire session on binding failure\n\nWhen a multichannel session binding request fails (e.g. wrong password),\nthe error path unconditionally sets sess->state = SMB2_SESSION_EXPIRED.\nHowever, during binding, sess points to the target session looked up via\nksmbd_session_lookup_slowpath() -- which belongs to another connection's\nuser. This allows a remote attacker to invalidate any active session by\nsimply sending a binding request with a wrong password (DoS).\n\nFix this by skipping session expiration when the failed request was\na binding attempt, since the session does not belong to the current\nconnection. The reference taken by ksmbd_session_lookup_slowpath() is\nstill correctly released via ksmbd_user_session_put().","state":"PUBLISHED","assigner":"Linux","published_at":"2026-04-22 14:16:44","updated_at":"2026-04-22 14:16:44"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/a897064a457056acb976e20e3007cdf553de340f","name":"https://git.kernel.org/stable/c/a897064a457056acb976e20e3007cdf553de340f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e0e5edc81b241c70355217de7e120c97c3429deb","name":"https://git.kernel.org/stable/c/e0e5edc81b241c70355217de7e120c97c3429deb","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6fafc4c4238e538969f1375f9ecdc6587c53f1cc","name":"https://git.kernel.org/stable/c/6fafc4c4238e538969f1375f9ecdc6587c53f1cc","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1d1888b4a7aec518b707f6eca0bf08992c0e8da3","name":"https://git.kernel.org/stable/c/1d1888b4a7aec518b707f6eca0bf08992c0e8da3","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9bbb19d21ded7d78645506f20d8c44895e3d0fb9","name":"https://git.kernel.org/stable/c/9bbb19d21ded7d78645506f20d8c44895e3d0fb9","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f5300690c23c5ac860499bb37dbc09cf43fd62e6","name":"https://git.kernel.org/stable/c/f5300690c23c5ac860499bb37dbc09cf43fd62e6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-31476","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31476","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 f5300690c23c5ac860499bb37dbc09cf43fd62e6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 6fafc4c4238e538969f1375f9ecdc6587c53f1cc git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 1d1888b4a7aec518b707f6eca0bf08992c0e8da3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 a897064a457056acb976e20e3007cdf553de340f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 e0e5edc81b241c70355217de7e120c97c3429deb git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 9bbb19d21ded7d78645506f20d8c44895e3d0fb9 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.168 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.131 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.80 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.21 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.11 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/smb/server/smb2pdu.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"f5300690c23c5ac860499bb37dbc09cf43fd62e6","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"6fafc4c4238e538969f1375f9ecdc6587c53f1cc","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"1d1888b4a7aec518b707f6eca0bf08992c0e8da3","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"a897064a457056acb976e20e3007cdf553de340f","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"e0e5edc81b241c70355217de7e120c97c3429deb","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"9bbb19d21ded7d78645506f20d8c44895e3d0fb9","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/smb/server/smb2pdu.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.168","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.131","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.80","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.21","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.11","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.168","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.131","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.80","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.21","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: do not expire session on binding failure\n\nWhen a multichannel session binding request fails (e.g. wrong password),\nthe error path unconditionally sets sess->state = SMB2_SESSION_EXPIRED.\nHowever, during binding, sess points to the target session looked up via\nksmbd_session_lookup_slowpath() -- which belongs to another connection's\nuser. This allows a remote attacker to invalidate any active session by\nsimply sending a binding request with a wrong password (DoS).\n\nFix this by skipping session expiration when the failed request was\na binding attempt, since the session does not belong to the current\nconnection. The reference taken by ksmbd_session_lookup_slowpath() is\nstill correctly released via ksmbd_user_session_put()."}],"providerMetadata":{"dateUpdated":"2026-04-22T13:54:04.779Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/f5300690c23c5ac860499bb37dbc09cf43fd62e6"},{"url":"https://git.kernel.org/stable/c/6fafc4c4238e538969f1375f9ecdc6587c53f1cc"},{"url":"https://git.kernel.org/stable/c/1d1888b4a7aec518b707f6eca0bf08992c0e8da3"},{"url":"https://git.kernel.org/stable/c/a897064a457056acb976e20e3007cdf553de340f"},{"url":"https://git.kernel.org/stable/c/e0e5edc81b241c70355217de7e120c97c3429deb"},{"url":"https://git.kernel.org/stable/c/9bbb19d21ded7d78645506f20d8c44895e3d0fb9"}],"title":"ksmbd: do not expire session on binding failure","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-31476","datePublished":"2026-04-22T13:54:04.779Z","dateReserved":"2026-03-09T15:48:24.098Z","dateUpdated":"2026-04-22T13:54:04.779Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-04-22 14:16:44","lastModifiedDate":"2026-04-22 14:16:44","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"31476","Ordinal":"1","Title":"ksmbd: do not expire session on binding failure","CVE":"CVE-2026-31476","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"31476","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: do not expire session on binding failure\n\nWhen a multichannel session binding request fails (e.g. wrong password),\nthe error path unconditionally sets sess->state = SMB2_SESSION_EXPIRED.\nHowever, during binding, sess points to the target session looked up via\nksmbd_session_lookup_slowpath() -- which belongs to another connection's\nuser. This allows a remote attacker to invalidate any active session by\nsimply sending a binding request with a wrong password (DoS).\n\nFix this by skipping session expiration when the failed request was\na binding attempt, since the session does not belong to the current\nconnection. The reference taken by ksmbd_session_lookup_slowpath() is\nstill correctly released via ksmbd_user_session_put().","Type":"Description","Title":"ksmbd: do not expire session on binding failure"}]}}}