CVE-2026-80846: Linux kernel · xfrm: drop ESP-in-TCP packets with no ingress device
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
- 0.1% chance of exploitation in 30 days – higher than 9% 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 in the Linux kernel to drop ESP-in-TCP packets when the ingress device cannot be resolved, preventing the NULL pointer dereference. Users should apply the official kernel updates that include this fix. Since this is a kernel-level vulnerability, upgrading to a patched kernel version is the recommended remediation. Patch status is not explicitly confirmed in the provided data; users should consult the vendor advisory or Linux kernel mailing lists for the specific fixed versions.
Description
In the Linux kernel, the following vulnerability has been resolved: xfrm: drop ESP-in-TCP packets with no ingress device ESP-in-TCP receives records through the TCP strparser. handle_esp() restores skb->dev from the saved skb_iif before passing the packet into the XFRM input path. Queued TCP data can be processed after the original ingress device has been removed, for example during veth or net namespace teardown. In that case dev_get_by_index_rcu() returns NULL. The XFRM IPv4 and IPv6 input paths both expect skb->dev to be valid while building the route lookup, so queued ESP-in-TCP data can dereference a NULL device. Drop the packet if the saved ingress device can no longer be resolved. Such a packet can no longer be routed through the normal XFRM receive path, and this preserves the existing behaviour for packets whose ingress device still exists.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80846 (opens in a new tab)
- git.kernel.org/stable/c/239d0f71af09dc2029fd4d730cb24b8c83aaa43a (opens in a new tab)
- git.kernel.org/stable/c/2dd1609cadff46c4b20ce53b91ab9cce1380456a (opens in a new tab)
- git.kernel.org/stable/c/328e40aa774b446969c69b654c52a051a95af8a1 (opens in a new tab)
- git.kernel.org/stable/c/6af5cdb03819a5ce6e945992635c6c5e91045367 (opens in a new tab)
- git.kernel.org/stable/c/7911e0236616487b89db6bd3ba3f408abd10eb23 (opens in a new tab)
- git.kernel.org/stable/c/943d95233b8b4a88994e244fcf466f8c403d63f1 (opens in a new tab)
- git.kernel.org/stable/c/c296d25efbc840be24de83f56d43bc47e714ace9 (opens in a new tab)
- git.kernel.org/stable/c/e1d7c5ac1c246ce5775f604515de0a59fbf2116e (opens in a new tab)
- git.kernel.org/stable/c/f00235f9d12301183d61f75fbe4105506f3e5140 (opens in a new tab)
- ubuntu.com/security/CVE-2026-80846 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-80846 (opens in a new tab)
- git.kernel.org/linus/e1d7c5ac1c246ce5775f604515de0a59fbf2116e (opens in a new tab)