# CVE-2025-40160: xen/events: Return -EEXIST for bound VIRQs

> A local attacker can trigger a kernel crash by attempting to bind a virtual IRQ to a different CPU than its current binding.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Nov 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-40160, DEBIAN-CVE-2025-40160, GHSA-86vm-hhg5-pm6h, ROOT-OS-DEBIAN-11-CVE-2025-40160, ROOT-OS-DEBIAN-12-CVE-2025-40160, ROOT-OS-DEBIAN-13-CVE-2025-40160, ROOT-OS-UBUNTU-2204-CVE-2025-40160, ROOT-OS-UBUNTU-2404-CVE-2025-40160, UBUNTU-CVE-2025-40160

## What is CVE-2025-40160?

CVE-2025-40160 is a denial of service vulnerability in Linux, published on 12 Nov 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

xen/events: Return -EEXIST for bound VIRQs

Change find_virq() to return -EEXIST when a VIRQ is bound to a
different CPU than the one passed in.  With that, remove the BUG_ON()
from bind_virq_to_irq() to propogate the error upwards.

Some VIRQs are per-cpu, but others are per-domain or global.  Those must
be bound to CPU0 and can then migrate elsewhere.  The lookup for
per-domain and global will probably fail when migrated off CPU 0,
especially when the current CPU is tracked.  This now returns -EEXIST
instead of BUG_ON().

A second call to bind a per-domain or global VIRQ is not expected, but
make it non-fatal to avoid trying to look up the irq, since we don't
know which per_cpu(virq_to_irq) it will be in.

## Which versions are affected by CVE-2025-40160?


## How do I fix CVE-2025-40160?

Apply the vendor's patch.

## Is CVE-2025-40160 being exploited?

There is no known exploitation of CVE-2025-40160 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-40160 and fix it if it is affected.

What it is: CVE-2025-40160 is a denial of service vulnerability in Linux, published on 12 Nov 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-40160 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-40160/ (Markdown: https://insights.sbomify.com/CVE-2025-40160/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40160
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40160
- OSV: https://osv.dev/vulnerability/CVE-2025-40160

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-40160/
Summaries are generated and may contain mistakes; the official description above is the record.