CVE-2026-89520: Linux kernel · sched/core: Make core-sched flips wait for in-flight selections
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
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 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 for this vulnerability has been implemented in the affected Linux kernel versions. Users should apply the official kernel updates provided by their Linux distribution vendors to remediate this issue. Since this is not a cloud service, remediation depends on patching the affected systems. No additional mitigation steps are indicated beyond applying the patches.
Description
A vulnerability in the Linux kernel's core scheduling mechanism was resolved. The issue involved core-sched flips not properly waiting for in-flight task selections, leading to potential lock state inconsistencies and resource leaks. This flaw affected specific Linux kernel versions used in various Ubuntu releases. The vulnerability has a CVSS score of 7.8, indicating a medium severity with high impact on confidentiality, integrity, and availability.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89520 (opens in a new tab)
- git.kernel.org/stable/c/23eda24f325a6e6d686d30ec75f2e9d6745e2015 (opens in a new tab)
- git.kernel.org/stable/c/9d69422ddaa13526c2223444e237d948d6e44728 (opens in a new tab)
- git.kernel.org/stable/c/f3629c63a4af3e491381780bc6c123cb498c4c40 (opens in a new tab)
- ubuntu.com/security/CVE-2026-89520 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89520 (opens in a new tab)
- git.kernel.org/linus/f3629c63a4af3e491381780bc6c123cb498c4c40 (opens in a new tab)
- git.kernel.org/stable/c/3e2511bffa93a639774a99e392181e21d28677e2 (opens in a new tab)