CVE-2026-68442: Linux kernel · btrfs: don't propagate EXTENT_FLAG_LOGGING to split extent maps
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 6.8.0-147.147 : patch Linux kernel soon.
Data as of 28 Oct 2026, 05:11 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1014.14~24.04.1 +26
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 12 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-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-8887-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8917-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8918-1 (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 addressing this vulnerability is available and has been incorporated into Linux kernel versions 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1014.14~24.04.1, and other related fixed versions. Users and administrators should update affected Linux kernel versions to these or later releases to remediate the issue. No additional mitigation steps are required beyond applying the official kernel updates.
Description
CVE-2026-68442 is a high-severity vulnerability in the Linux kernel's btrfs filesystem. It involves improper handling of the EXTENT_FLAG_LOGGING flag when splitting extent maps, which can lead to a use-after-free condition. This flaw was introduced by a code change that caused the flag to be incorrectly propagated and never cleared on split extent maps. The issue can trigger kernel warnings and potentially compromise system stability or security. The vulnerability affects specific Linux kernel versions prior to 6.8.0 and 7.0.0 releases. A patch is available and has been incorporated into fixed kernel versions.
References
- ubuntu.com/security/CVE-2026-68442 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-68442 (opens in a new tab)
- git.kernel.org/stable/c/5eff4d5b17fa1950e80bfd1ba43dc0699e61a644 (opens in a new tab)
- git.kernel.org/stable/c/2a9246a424f45f33a1b8367052611ebe874868ad (opens in a new tab)
- git.kernel.org/stable/c/9304713b70e7e1450e3a76e758836fe5391bfa95 (opens in a new tab)
- git.kernel.org/stable/c/0e465c63f103a5ce6849614d6bda048d70eebec8 (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-8887-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8917-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8918-1 (opens in a new tab)