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VulnerabilityPublished Updated

CVE-2025-40179: Linux kernel · ext4: verify orphan file size is not too big

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · fixed in 5.15.0-1100.107~20.04.2 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:05 UTC

Severity
Medium

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS
0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 5.15.0-1100.107~20.04.2, 5.15.0-1110.119~20.04.1, 5.15.0-1100.109~20.04.1 +67

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 12 Nov 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@6.17.0-14.14?arch=source&distro=questingOther threatsAffected
  • <6.17.0-14.14
Fixed in
  • 6.17.0-14.14
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1007.7?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1007.7
Fixed in
  • 6.17.0-1007.7
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1008.8?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1008.8
Fixed in
  • 6.17.0-1008.8
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?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@6.17.0-1007.7?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1007.7
Fixed in
  • 6.17.0-1007.7
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1007.7?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1007.7
Fixed in
  • 6.17.0-1007.7

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

Description

In the Linux kernel, the following vulnerability has been resolved: ext4: verify orphan file size is not too big In principle orphan file can be arbitrarily large. However orphan replay needs to traverse it all and we also pin all its buffers in memory. Thus filesystems with absurdly large orphan files can lead to big amounts of memory consumed. Limit orphan file size to a sane value and also use kvmalloc() for allocating array of block descriptor structures to avoid large order allocations for sane but large orphan files.

References

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