CVE-2026-89756: Linux kernel · mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()
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
- 0.1% chance of exploitation in 30 days – higher than 9% 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 is available that replaces the use of cond_resched() with cond_resched_tasks_rcu_qs() in the migrate_pages_batch() function to properly report RCU-tasks quiescent states. Users should apply the official kernel updates that include this fix. Patch status is not explicitly confirmed in the provided data; therefore, check the vendor advisory for current remediation guidance.
Description
A vulnerability in the Linux kernel's memory migration code causes the migrating task to stall the Tasks-RCU grace period for extended durations. This happens because the migrate_pages_batch() function unmaps pages in a way that triggers expensive KVM MMU notifier callbacks, and on PREEMPTION kernels, the quiescent state is not properly reported, leading to long stalls. This issue affects certain Linux kernel versions and has been resolved by changing the quiescent state reporting mechanism.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89756 (opens in a new tab)
- git.kernel.org/stable/c/4996a7bc01ef35570664854dac2530c604981039 (opens in a new tab)
- git.kernel.org/stable/c/5dc0daff0341c6baba19c38f47d299ac831d7e99 (opens in a new tab)
- git.kernel.org/stable/c/66734981b4d3c105223a13c827c9c73be18d91ad (opens in a new tab)
- git.kernel.org/stable/c/efe8f86c0916f0f74eea74ae21a3b37f728c6bad (opens in a new tab)
- msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-89756.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-2026-89756 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89756 (opens in a new tab)
- git.kernel.org/linus/efe8f86c0916f0f74eea74ae21a3b37f728c6bad (opens in a new tab)