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VulnerabilityPublished Updated

CVE-2025-40025: Linux kernel · f2fs: fix to do sanity check on node footer for non inode dnode

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · CVSS 7.8 High · fixed in 6.8.0-1035.38 : patch Linux kernel soon.

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 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 6.8.0-1035.38, 6.17.0-1006.6, 6.17.0-7.7 +4
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 28 Oct 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

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threatsAffected
  • <6.17.0-7.7
Fixed in
  • 6.17.0-7.7
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1004.4
Fixed in
  • 6.17.0-1004.4
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1006.6
Fixed in
  • 6.17.0-1006.6
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threatsAffected
  • 6.17.0-1003.3 – 6.17.0-1017.17
10 affected builds
Fixed in–
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1004.4
Fixed in
  • 6.17.0-1004.4
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1005.5
Fixed in
  • 6.17.0-1005.5

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available and included in updated Linux kernel packages released by Ubuntu (see USN-7906-1 and USN-7906-2). Users should apply the kernel updates and reboot their systems to fully remediate the issue. Due to ABI changes, third-party kernel modules must be recompiled and reinstalled after updating. No additional mitigations are required beyond applying the official fixes.

Description

A vulnerability in the Linux kernel's F2FS file system was fixed to add a sanity check on the node footer for non-inode dnodes. The flaw could cause a kernel panic due to inconsistent truncation range detection when a non-inode dnode is misinterpreted as an inode. This issue was reported by syzbot and affects multiple Linux kernel versions prior to 6.17.0-7.7 and certain older versions. The fix introduces a new node type to prevent misparsing and potential system crashes. Ubuntu has released updated kernel packages addressing this and other kernel vulnerabilities.

References

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