CVE-2025-40084: Linux kernel · ksmbd: transport_ipc: validate payload size before reading handle
Source GCVE Database
Not known to be exploited · CVSS 7.1 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 29 Oct 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
A fix has been implemented in the Linux kernel to validate the payload size before reading the handle in ksmbd. Users should apply the official kernel updates that include this fix once available.
Description
A vulnerability in the Linux kernel's ksmbd component was resolved by validating the payload size before reading a 4-byte handle. The function handle_response() previously dereferenced the payload as a 4 bytes without confirming the payload was at least that size, allowing a malformed or truncated message to cause an out-of-bounds read. The fix ensures the size is checked before dereferencing to prevent this issue.
References
- nvd.nist.gov/vuln/detail/CVE-2025-40084 (opens in a new tab)
- git.kernel.org/stable/c/2dc125f5da134c0915a840b62565c60a595673dd (opens in a new tab)
- git.kernel.org/stable/c/6f40e50ceb99fc8ef37e5c56e2ec1d162733fef0 (opens in a new tab)
- git.kernel.org/stable/c/867ffd9d67285612da3f0498ca618297f8e41f01 (opens in a new tab)
- git.kernel.org/stable/c/898d527ed94c19980a4d848f10057f1fed578ffb (opens in a new tab)
- git.kernel.org/stable/c/a02e432d5130da4c723aabe1205bac805889fdb2 (opens in a new tab)