CVE-2025-68809: Linux kernel · ksmbd: vfs: fix race on m_flags in vfs_cache
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 9.1 Critical · fixed in ee63729760f5b61a66f345c54dc4c7514e62383d : patch Linux kernel as a priority.
Data as of 30 Oct 2026, 12:49 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 9.1 |
|---|
- Patch
- Available – fixed in ee63729760f5b61a66f345c54dc4c7514e62383d, ccc78781041589ea383e61d5d7a1e9a31b210b93, a4fd1fdf505facfae26b5654c9eff321f4cbc1a7 +2
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 13 Jan 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 30 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix is available and has been applied in specific Linux kernel commits. Users should update to a Linux kernel version that includes the fix identified by the commits ee63729760f5b61a66f345c54dc4c7514e62383d, ccc78781041589ea383e61d5d7a1e9a31b210b93, a4fd1fdf505facfae26b5654c9eff321f4cbc1a7, 991f8a79db99b14c48d20d2052c82d65b9186cad, or 5adad9727a815c26013b0d41cfee92ffa7d4037c. The affected version is Linux kernel 5.15. No additional mitigation is required beyond applying the official patch.
Description
CVE-2025-68809 is a critical vulnerability in the Linux kernel's ksmbd component related to a race condition on the m_flags field in vfs_cache. The issue arises from inconsistent locking when accessing m_flags, which tracks delete-on-close and pending-delete states. This can lead to data races when multiple threads concurrently open, close, or delete the same file, causing files to either remain on disk after deletion or disappear prematurely. The vulnerability has been fixed by unifying locking around m_flags to prevent race conditions while preserving expected delete-on-close behavior.
References
- git.kernel.org/stable/c/a4fd1fdf505facfae26b5654c9eff321f4cbc1a7 (opens in a new tab)
- git.kernel.org/stable/c/5adad9727a815c26013b0d41cfee92ffa7d4037c (opens in a new tab)
- git.kernel.org/stable/c/ccc78781041589ea383e61d5d7a1e9a31b210b93 (opens in a new tab)
- git.kernel.org/stable/c/ee63729760f5b61a66f345c54dc4c7514e62383d (opens in a new tab)
- git.kernel.org/stable/c/991f8a79db99b14c48d20d2052c82d65b9186cad (opens in a new tab)