CVE-2025-40025: Linux kernel · f2fs: fix to do sanity check on node footer for non inode dnode
Affects Linux kernelSource GCVE Database
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
- 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:HExploitation evidence
Disclosed: evidence found.
CVE published 28 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
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threats | Affected
| Fixed in
|
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
- ubuntu.com/security/CVE-2025-40025 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-40025 (opens in a new tab)
- git.kernel.org/stable/c/186098f34b8a5d65eb828f952c8cc56272c60ea0 (opens in a new tab)
- git.kernel.org/stable/c/c18ecd99e0c707ef8f83cace861cbc3162f4fdf1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7906-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7906-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7906-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8781-1 (opens in a new tab)