CVE-2026-45912: Linux kernel · ext4: don't cache extent during splitting extent
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 6.8.0-1060.63~22.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1060.63~22.04.1, 6.8.0-1063.69~22.04.1, 6.8.0-1060.61~22.04.1 +24
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 May 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 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde@7.0.0-1008.8?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-40.40?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1019.19?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1020.20?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1020.22?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 should be applied to affected Linux kernel versions. The vendor advisory from Ubuntu confirms that this and other kernel vulnerabilities have been fixed in updated kernel packages. Users should update their Linux kernel to the fixed versions provided by their distribution. No additional mitigation is required beyond applying the official fix.
Description
A vulnerability in the Linux kernel's ext4 filesystem was resolved that involved improper caching of extents during the splitting process. Caching extents while splitting could leave stale extents in the extent status tree, causing errors in space accounting when delayed writes occur. This flaw affects specific Linux kernel versions and has been addressed in security updates.
References
- ubuntu.com/security/CVE-2026-45912 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-45912 (opens in a new tab)
- git.kernel.org/linus/8b4b19a2f96348d70bfa306ef7d4a13b0bcbea79 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8497-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8498-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8499-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8492-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8597-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8606-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8607-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8609-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-3 (opens in a new tab)