CVE-2026-31476: Linux kernel · ksmbd: do not expire session on binding failure
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.2 High.
Data as of 12 Nov 2026, 00:34 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 8.2 |
|---|
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:HExploitation evidence
Disclosed: evidence found.
CVE published 22 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 11 Nov 2026.
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: do not expire session on binding failure When a multichannel session binding request fails (e.g. wrong password), the error path unconditionally sets sess->state = SMB2_SESSION_EXPIRED. However, during binding, sess points to the target session looked up via ksmbd_session_lookup_slowpath() -- which belongs to another connection's user. This allows a remote attacker to invalidate any active session by simply sending a binding request with a wrong password (DoS). Fix this by skipping session expiration when the failed request was a binding attempt, since the session does not belong to the current connection. The reference taken by ksmbd_session_lookup_slowpath() is still correctly released via ksmbd_user_session_put().
References
- git.kernel.org/stable/c/4642ea35c03cf3d3558c009df4757cdb7af3f82d (opens in a new tab)
- git.kernel.org/stable/c/f5300690c23c5ac860499bb37dbc09cf43fd62e6 (opens in a new tab)
- git.kernel.org/stable/c/6fafc4c4238e538969f1375f9ecdc6587c53f1cc (opens in a new tab)
- git.kernel.org/stable/c/1d1888b4a7aec518b707f6eca0bf08992c0e8da3 (opens in a new tab)
- git.kernel.org/stable/c/a897064a457056acb976e20e3007cdf553de340f (opens in a new tab)
- git.kernel.org/stable/c/e0e5edc81b241c70355217de7e120c97c3429deb (opens in a new tab)
- git.kernel.org/stable/c/9bbb19d21ded7d78645506f20d8c44895e3d0fb9 (opens in a new tab)