CVE-2026-80792: Linux kernel · ipv6: fix use-after-free in ip6_finish_output2()
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
The vulnerability description indicates that a fix has been implemented in the Linux kernel source code by re-fetching the IPv6 header and destination address pointer after lwtunnel_xmit() returns. Users should monitor official Linux kernel advisories and update to a fixed kernel version once available.
Description
In the Linux kernel, the following vulnerability has been resolved: ipv6: fix use-after-free in ip6_finish_output2() ip6_finish_output2() caches a pointer to the IPv6 destination address (daddr) before invoking lwtunnel_xmit(). The LWT-BPF transmit path or other encapsulation operations within lwtunnel_xmit() can reallocate the skb head, freeing the memory that daddr points to. When lwtunnel_xmit() returns LWTUNNEL_XMIT_CONTINUE, the function continues to use the stale daddr pointer to compute the nexthop and to look up or create the neighbour entry. This results in a use-after-free read, which can leak sensitive kernel data, pollute the neighbour table with arbitrary values, misdirect traffic, or crash the system. Fix this by re-fetching the IPv6 header and the destination address pointer after lwtunnel_xmit() returns LWTUNNEL_XMIT_CONTINUE, ensuring that the subsequent nexthop computation and neighbour lookup operate on valid memory.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80792 (opens in a new tab)
- git.kernel.org/stable/c/087ee0d914aaae929f1660c9ca878e367655ba1a (opens in a new tab)
- git.kernel.org/stable/c/3c770ac4e6f07af7c7b40c474a3efc61ffed7862 (opens in a new tab)
- git.kernel.org/stable/c/3dc98e5fe82d069dd29b124ffbdb679331dfea43 (opens in a new tab)
- git.kernel.org/stable/c/73a187384a8c8b983c7fea046d716b6752a1e7a3 (opens in a new tab)
- git.kernel.org/stable/c/75e0a544ebe9af663ef53ca21e9e9185c51fb54a (opens in a new tab)
- git.kernel.org/stable/c/99219c82804f266189388e8bf1cf5135d10d5515 (opens in a new tab)
- git.kernel.org/stable/c/c95f01b78266828a57060d754fcbfc92123a98ed (opens in a new tab)
- git.kernel.org/stable/c/d0d48d999b0eee6bb176ef4e39d9be868fa80f7e (opens in a new tab)
- git.kernel.org/stable/c/d960881b9312e781a3429aabceb223ce6b7c882f (opens in a new tab)
- ubuntu.com/security/CVE-2026-80792 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-80792 (opens in a new tab)
- git.kernel.org/linus/d0d48d999b0eee6bb176ef4e39d9be868fa80f7e (opens in a new tab)