CVE-2026-80636: Linux kernel · netfilter: conntrack: revert ct extension genid infrastructure
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 6.8.0-147.147 : update Linux kernel when convenient.
Data as of 28 Oct 2026, 01:00 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- Patch
- Available – fixed in 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1014.14~24.04.1 +25
Exploitation evidence
Disclosed: evidence found.
CVE published 28 Aug 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
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8917-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8918-1 (opens in a new tab)
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.
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: revert ct extension genid infrastructure This infrastructure is not used anymore after moving ct timeout and helper to use datapath refcount to track object use. Revert commit c56716c69ce1 ("netfilter: extensions: introduce extension genid count") this patch disables all ct extensions (leading to NULL) for unconfirmed conntracks, when this is only targeted at ct helper and ct timeout. There is also codebase that dereferences the ct extension without checking for NULL which could lead to crash.
References
- ubuntu.com/security/CVE-2026-80636 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-80636 (opens in a new tab)
- git.kernel.org/linus/35e21a4dccc5c255ba59ccfbfeb4629ed21da972 (opens in a new tab)
- git.kernel.org/stable/c/35e21a4dccc5c255ba59ccfbfeb4629ed21da972 (opens in a new tab)
- git.kernel.org/stable/c/61eab1d0237eb513fe73e391a5926ee70092c325 (opens in a new tab)
- git.kernel.org/stable/c/6bba4846f196d081bf553391d12b5a73dcc48685 (opens in a new tab)
- git.kernel.org/stable/c/a052a94bcc629acaecc2ce42a4af77f8fa399757 (opens in a new tab)
- git.kernel.org/stable/c/d53eecbca16f056abba274075cb15120ab062518 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8917-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8918-1 (opens in a new tab)