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VulnerabilityPublished Updated

CVE-2025-40233: Linux kernel · ocfs2: clear extent cache after moving/defragmenting extents

Source GCVE Database

0

Not known to be exploited · CVSS 7.8 High.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
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:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 4 Dec 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

The described fix involves clearing the extent map cache after extent move or defragment operations. Users should monitor official Linux kernel advisories for patches addressing CVE-2025-40233 and apply updates when available.

Description

A vulnerability in the Linux kernel's ocfs2 filesystem occurs due to stale extent map cache after moving or defragmenting extents. This stale cache causes a mismatch between cached extent flags and the actual flags on disk, triggering a kernel BUG_ON condition. The issue arises specifically when reflinked extents are moved or defragmented without invalidating the extent map cache. The vulnerability has been resolved by clearing the extent map cache after each extent move or defragment operation to ensure fresh data is read from disk.

References

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