CVE-2026-80681: Linux kernel · vxlan: re-fetch eth header after route_shortcircuit()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 42% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +26
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation 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.
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 patch is available for this vulnerability. Users should apply the official Linux kernel updates that address CVE-2026-80681 to remediate the issue. After updating, a system reboot is required to ensure the fix is applied. No additional mitigation steps are indicated by the vendor advisory.
Description
A use-after-free vulnerability was identified and resolved in the Linux kernel's VXLAN implementation. The issue occurs because the Ethernet header pointer is cached before a function call that may reallocate memory, leading to a dangling pointer and potential use-after-free when accessing the Ethernet destination address. This vulnerability has a high severity score of 9.8 CVSS and affects specific Linux kernel versions. A patch is available to fix this flaw by updating the Ethernet header pointer after the memory reallocation function call.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80681 (opens in a new tab)
- git.kernel.org/stable/c/1235e017aa11cf01e91b613c4c5ed6aa28934fff (opens in a new tab)
- git.kernel.org/stable/c/1395a676ec15a0a02a2a6d86602324f2d5fd41d5 (opens in a new tab)
- git.kernel.org/stable/c/1511631b7cfc4152b10a0a9d04c7a0bf2ddf4585 (opens in a new tab)
- git.kernel.org/stable/c/1b7f7b653e3557690047c62f03b80a24ea5a58a5 (opens in a new tab)
- git.kernel.org/stable/c/2355c8c26d2aa1b4385b369e67202e47d460d555 (opens in a new tab)
- git.kernel.org/stable/c/6375093eb45cd7d89f1945f939eeae3b29d79f56 (opens in a new tab)
- git.kernel.org/stable/c/bf045341dfb3e767f0ff94cf240ce3c371973bd4 (opens in a new tab)
- git.kernel.org/stable/c/c9dceac9e1c7c772c43c732fc0d325e72835801a (opens in a new tab)
- ubuntu.com/security/CVE-2026-80681 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-80681 (opens in a new tab)
- git.kernel.org/linus/1395a676ec15a0a02a2a6d86602324f2d5fd41d5 (opens in a new tab)
- msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-80681.json (opens in a new tab)
- support.microsoft.com/lifecycle (opens in a new tab)
- first.org/cvss (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-2 (opens in a new tab)