# CVE-2022-26356: Race condition in xen

> A race condition in Xen's dirty VRAM tracking allows memory leaks, potentially leading to denial of service.

- **Severity:** Medium 5.6 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/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:** 5 Apr 2022
- **Updated:** 3 Aug 2024
- **Also known as:** ALPINE-CVE-2022-26356, DEBIAN-CVE-2022-26356, GHSA-wqf3-h5g7-w9q8, UBUNTU-CVE-2022-26356

## What is CVE-2022-26356?

CVE-2022-26356 is a medium-severity vulnerability in Debian Debian Linux, published on 5 Apr 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Racy interactions between dirty vram tracking and paging log dirty hypercalls Activation of log dirty mode done by XEN_DMOP_track_dirty_vram (was named HVMOP_track_dirty_vram before Xen 4.9) is racy with ongoing log dirty hypercalls. A suitably timed call to XEN_DMOP_track_dirty_vram can enable log dirty while another CPU is still in the process of tearing down the structures related to a previously enabled log dirty mode (XEN_DOMCTL_SHADOW_OP_OFF). This is due to lack of mutually exclusive locking between both operations and can lead to entries being added in already freed slots, resulting in a memory leak.

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2022-26356?

It affects 3 products.


Products: Debian Debian Linux, Fedoraproject Fedora, Xen Xen.

## How do I fix CVE-2022-26356?

Apply the vendor's patch.

## Is CVE-2022-26356 being exploited?

There is no known exploitation of CVE-2022-26356 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-26356 and fix it if it is affected.

What it is: CVE-2022-26356 is a medium-severity vulnerability in Debian Debian Linux, published on 5 Apr 2022. 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-2022-26356 in the wild and no public exploit code.

Affected product: Debian Debian 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-2022-26356/ (Markdown: https://insights.sbomify.com/CVE-2022-26356/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-26356
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-26356
- OSV: https://osv.dev/vulnerability/CVE-2022-26356

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-26356/
Summaries are generated and may contain mistakes; the official description above is the record.