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 28 Oct 2026, 05:11 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 +56
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.
Patches and advisories
- 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)
- ubuntu.com/security/notices/USN-8887-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-2 (opens in a new tab)
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. Fixed versions include multiple releases in the 5.15.0 kernel series (e.g., 5.15.0-1117.124~20.04.1 and later). Users should upgrade to these fixed versions to remediate the vulnerability. No additional mitigation is required beyond applying the official kernel updates.
Description
CVE-2026-72225 is a high-severity vulnerability in the Linux kernel's jbd2 journaling subsystem. It involves an integer underflow in the function jbd2_journal_initialize_fast_commit(), where unsigned integer subtraction can wrap around, bypassing capacity checks and causing corruption of journal metadata. This corruption can lead to journal aborts and potentially compromise system integrity. The issue affects multiple Linux kernel versions prior to fixed releases in the 5.15.0 series. A patch is available that adds proper validation to prevent the underflow condition.
References
- 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)
- 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/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)