CVE-2025-40273: Linux kernel · NFSD: free copynotify stateid in nfs4_free_ol_stateid()
Source GCVE Database
Not known to be exploited · CVSS 8.8 High.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 36% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 7 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
AI-suggested
Until an official fix is available, monitor for kernel updates addressing this issue and consider applying kernel patches or updates as recommended by the Linux kernel maintainers.
Description
A use-after-free vulnerability in the Linux kernel's NFS server (nfsd) was resolved by properly freeing associated copynotify stateids in the nfs4_free_ol_stateid() function. The issue occurs when a parent stateid is freed without freeing its associated copynotify stateids, leading to list corruption and kernel warnings or crashes. This can happen after a client reboot and session recreation, causing internal kernel errors and potential denial of service.
References
- nvd.nist.gov/vuln/detail/CVE-2025-40273 (opens in a new tab)
- git.kernel.org/stable/c/29fbb3ad4018ca2b0988fbac76f4c694cc6d7e66 (opens in a new tab)
- git.kernel.org/stable/c/4aa17144d5abc3c756883e3a010246f0dba8b468 (opens in a new tab)
- git.kernel.org/stable/c/839f56f626723f36904764858467e7a3881b975d (opens in a new tab)
- git.kernel.org/stable/c/935a2dc8928670bb2c37e21025331e61ec48ccf4 (opens in a new tab)
- git.kernel.org/stable/c/b114996a095da39e38410a0328d4a8aca8c36088 (opens in a new tab)
- git.kernel.org/stable/c/d7be15a634aa3874827d0d3ea47452ee878b8df7 (opens in a new tab)
- git.kernel.org/stable/c/f67ad9b33b0e6f00d2acc67cbf9cfa5c756be5fb (opens in a new tab)