CVE-2026-72225: Linux kernel · jbd2: fix integer underflow in jbd2_journal_initialize_fast_commit()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +42
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 15 Aug 2026
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 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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 should be applied to affected Linux kernel versions. The fix involves validating the input parameters to prevent integer underflow in the jbd2 subsystem. Users should update to the fixed kernel versions as provided by their distribution vendors. No additional mitigation is indicated by the vendor advisory.
Description
A vulnerability in the Linux kernel's jbd2 subsystem caused an integer underflow in the jbd2_journal_initialize_fast_commit() function. This underflow occurs because unsigned variables are subtracted without proper bounds checking, leading to corruption of journal variables and a journal abort. The issue has been fixed by adding a check before the subtraction to prevent underflow.
References
- nvd.nist.gov/vuln/detail/CVE-2026-72225 (opens in a new tab)
- git.kernel.org/stable/c/289a2ca0c9b7eae74f93fc213b0b971669b8683d (opens in a new tab)
- git.kernel.org/stable/c/4450dcaadf7d4aae8b6e4223b5d6ee4eb77097a9 (opens in a new tab)
- git.kernel.org/stable/c/4b48dcb88bb9117e3d3f051175a9a8b7cff7f8b6 (opens in a new tab)
- git.kernel.org/stable/c/78955fdce8ff654e6d33a2fa90882a1e7eb26330 (opens in a new tab)
- git.kernel.org/stable/c/a58fc10adf503969fec2007b5afe8987258046c4 (opens in a new tab)
- git.kernel.org/stable/c/e144ad0250f77e23e28949587b8b57e40dc3b512 (opens in a new tab)
- git.kernel.org/stable/c/fb9b49618ed7296ebfad62a3835da8945f727001 (opens in a new tab)
- ubuntu.com/security/CVE-2026-72225 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-72225 (opens in a new tab)
- git.kernel.org/linus/289a2ca0c9b7eae74f93fc213b0b971669b8683d (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)