CVE-2026-80845: Linux kernel · xfrm: avoid lock inversion in nat keepalive work
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 12:55 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- 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.
Exploitation evidence
Disclosed: evidence found.
CVE published 4 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 restructures the locking mechanism to avoid deadlocks. Users should apply the official Linux kernel updates that include this fix.
Description
In the Linux kernel, the following vulnerability has been resolved: xfrm: avoid lock inversion in nat keepalive work nat_keepalive_work() walks the state table while xfrm_state_walk() holds net->xfrm.xfrm_state_lock. Its callback then acquires x->lock, which conflicts with the delete path taking the same locks in reverse order via xfrm_state_delete() and __xfrm_state_delete(). This creates an AB-BA deadlock that is reported by lockdep when a NAT keepalive worker races with SA deletion. Fix this by splitting the keepalive walk into two phases. First, collect the candidate states while the walk holds xfrm_state_lock and take a reference on each state. Then, after the walk completes, process each collected state and acquire x->lock without nesting it under xfrm_state_lock.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80845 (opens in a new tab)
- git.kernel.org/stable/c/5c86c895d1cac81a71ead3005084c6265cf6a7a5 (opens in a new tab)
- git.kernel.org/stable/c/763fe700b7c58ad64fe5202c5638848244dd4127 (opens in a new tab)
- git.kernel.org/stable/c/89ef3a2e1e4682ab82b0455ce113f8c39fb9e50d (opens in a new tab)
- git.kernel.org/stable/c/a9fa05b7a1246797748d15771052639e0d3cabf1 (opens in a new tab)
- git.kernel.org/stable/c/ea09210462316e5235a25eccb11ad0708d86615e (opens in a new tab)
- ubuntu.com/security/CVE-2026-80845 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-80845 (opens in a new tab)
- git.kernel.org/linus/763fe700b7c58ad64fe5202c5638848244dd4127 (opens in a new tab)