CVE-2026-90302: Linux kernel · ocfs2: synchronize heartbeat callbacks with o2net teardown
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 17:16 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 17 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 patch series has been released that fixes the race conditions by synchronizing heartbeat callbacks with the o2net teardown process. Users should apply the official Linux kernel updates that include these patches. Since this is a kernel-level issue, updating to a patched kernel version is the recommended remediation. Patch status is confirmed by the vendor advisory describing the fix. No additional mitigation steps are indicated.
Description
A race condition vulnerability in the Linux kernel's OCFS2 cluster filesystem was resolved by synchronizing heartbeat callbacks with the o2net teardown process. The flaw involved use-after-free errors during concurrent teardown and heartbeat callback execution, potentially causing kernel memory corruption. The patch ensures heartbeat callbacks remain registered until local-node teardown completes, preventing stale or conflicting network state updates.
References
- ubuntu.com/security/CVE-2026-90302 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-90302 (opens in a new tab)
- git.kernel.org/linus/3e326f3bf16506873777444608e8b715aab74a7a (opens in a new tab)
- msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-90302.json (opens in a new tab)
- support.microsoft.com/lifecycle (opens in a new tab)
- first.org/cvss (opens in a new tab)