# CVE-2025-40024: vhost: Take a reference on the task in struct vhost_task.

> A use-after-free in the Linux kernel vhost subsystem allows attackers to cause a denial of service or potentially execute code via race conditions.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** 24 Oct 2025
- **Updated:** 5 Aug 2026
- **Also known as:** AZL-68799, BELL-CVE-2025-40024, DEBIAN-CVE-2025-40024, GHSA-798j-2qwm-wpvm, ROOT-OS-DEBIAN-13-CVE-2025-40024, ROOT-OS-UBUNTU-2404-CVE-2025-40024, UBUNTU-CVE-2025-40024

## What is CVE-2025-40024?

CVE-2025-40024 is a high-severity use after free vulnerability in Linux, published on 24 Oct 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:

vhost: Take a reference on the task in struct vhost_task.

vhost_task_create() creates a task and keeps a reference to its
task_struct. That task may exit early via a signal and its task_struct
will be released.
A pending vhost_task_wake() will then attempt to wake the task and
access a task_struct which is no longer there.

Acquire a reference on the task_struct while creating the thread and
release the reference while the struct vhost_task itself is removed.
If the task exits early due to a signal, then the vhost_task_wake() will
still access a valid task_struct. The wake is safe and will be skipped
in this case.

## Which versions are affected by CVE-2025-40024?


## How do I fix CVE-2025-40024?

Apply the vendor's patch.

## Is CVE-2025-40024 being exploited?

There is no known exploitation of CVE-2025-40024 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-40024 and fix it if it is affected.

What it is: CVE-2025-40024 is a high-severity use after free vulnerability in Linux, published on 24 Oct 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-2025-40024 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-2025-40024/ (Markdown: https://insights.sbomify.com/CVE-2025-40024/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40024
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40024
- OSV: https://osv.dev/vulnerability/CVE-2025-40024

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-40024/
Summaries are generated and may contain mistakes; the official description above is the record.