CVE-2026-89567: Linux kernel · jbd2: bound shrinker scans by examined checkpoint buffers
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 14:05 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 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
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 fix has been implemented that correctly accounts for busy buffers in the scan budget, preventing excessive lock hold times. Users should apply the official kernel updates that include this fix. Since this is a kernel-level issue, upgrading to patched kernel versions is the recommended remediation.
Description
A vulnerability in the Linux kernel's jbd2 component allows excessive scanning of checkpoint buffers while holding a lock, potentially causing soft lockups or RCU stalls. The issue arises because busy buffers do not reduce the scan budget, leading to prolonged lock hold times when checkpoint transactions contain many busy buffers. This vulnerability has been resolved by adjusting the scan budget accounting to include busy buffers during scanning, restoring previous scan-budget semantics.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89567 (opens in a new tab)
- git.kernel.org/stable/c/15cb16496446b94e67f7abcb049b8e2c75cd3d02 (opens in a new tab)
- git.kernel.org/stable/c/71c6b872c746465fa4b5def239cb296173ca8216 (opens in a new tab)
- git.kernel.org/stable/c/c2c0fb364685b8996c357d3b050394959b29d6e0 (opens in a new tab)
- git.kernel.org/stable/c/edf5fcd0469b7467bd5b37a79502c8d9c3257dbb (opens in a new tab)
- msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-89567.json (opens in a new tab)
- support.microsoft.com/lifecycle (opens in a new tab)
- first.org/cvss (opens in a new tab)
- ubuntu.com/security/CVE-2026-89567 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89567 (opens in a new tab)
- git.kernel.org/linus/15cb16496446b94e67f7abcb049b8e2c75cd3d02 (opens in a new tab)