CVE-2026-74624: Linux kernel · netfilter: nf_conntrack: defer invalid log until after unlock TCP and SCTP conntrack
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.5 High : upgrade to 6.8.0-1036.39 soon.
Data as of 28 Oct 2026, 01:00 UTC
- Patch
- Available – fixed in 6.8.0-1036.39
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 22 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 the Ubuntu linux-nvidia-tegra package to 6.8.0-1036.39.
Patches and advisories
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: nf_conntrack: defer invalid log until after unlock TCP and SCTP conntrack paths can emit invalid-packet logs while ct->lock is still held. When invalid logging is routed to nfnetlink_log and conntrack export is enabled, the log path can re-enter conntrack netlink glue and dump the same conntrack again. Protocol attribute dumping may take ct->lock, so logging while holding that lock can deadlock. Defer the TCP invalid logs by storing only the minimal log context while ct->lock is held and emitting the log after unlocking. Also make the TCP timeout-lowering invalid path return whether a log is needed, then emit that log after unlocking. Do the same for the SCTP invalid state-transition log that can be reached while ct->lock is held. Add a lockdep assertion to nf_ct_l4proto_log_invalid() so future callers that log invalid conntracks while holding ct->lock are caught outside TCP and SCTP as well.
References
- ubuntu.com/security/CVE-2026-74624 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74624 (opens in a new tab)
- git.kernel.org/stable/c/c0224327b7cbed9d3198e8dbec847281053dcd06 (opens in a new tab)
- git.kernel.org/stable/c/ca97360eba4b3dc67f1804625542f4ccc774242a (opens in a new tab)
- git.kernel.org/stable/c/63853eb20bba4e00b7cd0b8cfc19337bbaaf5037 (opens in a new tab)
- git.kernel.org/stable/c/2d19b95c9723001f214f7a47d67b09f46238f200 (opens in a new tab)
- git.kernel.org/stable/c/9480fcf70a5aa9d320088a01c95df0e5e6391f4a (opens in a new tab)
- git.kernel.org/stable/c/0424186d570aa4d1ad17f516afb86bd9eaa4f42e (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)