# CVE-2023-52731: fbdev: Fix invalid page access after closing deferred I/O devices

> A use-after-free vulnerability in the Linux kernel's fbdev subsystem allows attackers to cause a system crash via delayed work processing after device closure.

- **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:** 21 May 2024
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2023-52731, DEBIAN-CVE-2023-52731, GHSA-w9fv-gm94-h938, UBUNTU-CVE-2023-52731

## What is CVE-2023-52731?

CVE-2023-52731 is a high-severity use after free vulnerability in Linux kernel, published on 21 May 2024. 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:

fbdev: Fix invalid page access after closing deferred I/O devices

When a fbdev with deferred I/O is once opened and closed, the dirty
pages still remain queued in the pageref list, and eventually later
those may be processed in the delayed work.  This may lead to a
corruption of pages, hitting an Oops.

This patch makes sure to cancel the delayed work and clean up the
pageref list at closing the device for addressing the bug.  A part of
the cleanup code is factored out as a new helper function that is
called from the common fb_release().

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2023-52731?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-52731?

Apply the vendor's patch.

## Is CVE-2023-52731 being exploited?

There is no known exploitation of CVE-2023-52731 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-52731 and fix it if it is affected.

What it is: CVE-2023-52731 is a high-severity use after free vulnerability in Linux kernel, published on 21 May 2024. 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-2023-52731 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2023-52731/ (Markdown: https://insights.sbomify.com/CVE-2023-52731/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-52731
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-52731
- OSV: https://osv.dev/vulnerability/CVE-2023-52731

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-52731/
Summaries are generated and may contain mistakes; the official description above is the record.