{"id":"CVE-2026-31476","summary":"ksmbd: do not expire session on binding failure","details":"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-\u003estate = 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().","modified":"2026-05-18T05:59:49.523905197Z","published":"2026-04-22T13:54:04.779Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31476.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1d1888b4a7aec518b707f6eca0bf08992c0e8da3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6fafc4c4238e538969f1375f9ecdc6587c53f1cc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9bbb19d21ded7d78645506f20d8c44895e3d0fb9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a897064a457056acb976e20e3007cdf553de340f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e0e5edc81b241c70355217de7e120c97c3429deb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f5300690c23c5ac860499bb37dbc09cf43fd62e6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31476.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31476"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"f5a544e3bab78142207e0242d22442db85ba1eff"},{"fixed":"f5300690c23c5ac860499bb37dbc09cf43fd62e6"},{"fixed":"6fafc4c4238e538969f1375f9ecdc6587c53f1cc"},{"fixed":"1d1888b4a7aec518b707f6eca0bf08992c0e8da3"},{"fixed":"a897064a457056acb976e20e3007cdf553de340f"},{"fixed":"e0e5edc81b241c70355217de7e120c97c3429deb"},{"fixed":"9bbb19d21ded7d78645506f20d8c44895e3d0fb9"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-31476.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.15.0"},{"fixed":"6.1.168"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.131"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.80"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.21"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-31476.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H"}]}