CVE-2025-40303: Linux kernel · btrfs: ensure no dirty metadata is written back for an fs with errors
Source GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% 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:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 8 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
A fix has been implemented in the Linux kernel to address this vulnerability by preventing dirty metadata writeback when the filesystem is in an error state. Users should apply the official kernel updates that include this fix. Patch status is not explicitly confirmed in the provided data; therefore, check the vendor advisory for current remediation guidance.
Description
A high-severity vulnerability in the Linux kernel's btrfs filesystem was resolved to prevent dirty metadata from being written back when the filesystem is in an error state. The issue could cause use-after-free conditions and filesystem corruption, especially when using RAID5 or RAID6 metadata configurations. The fix prevents submission of writeback operations for dirty metadata if the filesystem is marked as errored, avoiding further corruption and crashes.
References
- nvd.nist.gov/vuln/detail/CVE-2025-40303 (opens in a new tab)
- git.kernel.org/stable/c/066ee13f05fbd82ada01883e51f0695172f98dff (opens in a new tab)
- git.kernel.org/stable/c/2618849f31e7cf51fadd4a5242458501a6d5b315 (opens in a new tab)
- git.kernel.org/stable/c/54a5b5a15588e3b0b294df31474d08a2678d4291 (opens in a new tab)
- git.kernel.org/stable/c/e2b3859067bf012d53c49b3f885fef40624a2c83 (opens in a new tab)