CVE-2026-89566: Linux kernel · jbd2: check need_resched() when skipping busy 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 in the Linux kernel to address this issue by adding the need_resched() check on the busy-buffer path. Users should apply the updated kernel versions containing this fix. No additional mitigation steps are indicated.
Description
A vulnerability in the Linux kernel's jbd2 component causes the shrinker to hold a lock for extended periods under memory pressure, potentially leading to soft lockups or RCU stalls. This occurs because the need_resched() check is skipped when busy checkpoint buffers are encountered, preventing timely rescheduling. The issue has been resolved by routing the busy-buffer path through the need_resched() check to allow prompt rescheduling and lock release.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89566 (opens in a new tab)
- git.kernel.org/stable/c/595cac7f1b32d009b97f83dd2b2d6a1a445e9bb4 (opens in a new tab)
- git.kernel.org/stable/c/f213e12ff5c9590b1034ae8da0e6d09665c772d0 (opens in a new tab)
- git.kernel.org/stable/c/f83c23286e54180cdc83a36463a60003534cc290 (opens in a new tab)
- git.kernel.org/stable/c/f9182a85991a0ad5cd2940df6db75f40ad90028c (opens in a new tab)
- ubuntu.com/security/CVE-2026-89566 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89566 (opens in a new tab)
- git.kernel.org/linus/f213e12ff5c9590b1034ae8da0e6d09665c772d0 (opens in a new tab)