# CVE-2026-22856: FreeRDP has a heap-use-after-free in create_irp_thread

> A race condition in FreeRDP's serial channel IRP thread tracking allows heap use-after-free, potentially leading to code execution or denial of service.

- **Severity:** Medium 6.8 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 14 Jan 2026
- **Updated:** 26 Feb 2026
- **Also known as:** CLSA-2026-1771407667, DEBIAN-CVE-2026-22856, GHSA-w842-c386-fxhv, UBUNTU-CVE-2026-22856

## What is CVE-2026-22856?

CVE-2026-22856 is a medium-severity use after free vulnerability in Freerdp Freerdp, published on 14 Jan 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, a race in the serial channel IRP thread tracking allows a heap use‑after‑free when one thread removes an entry from serial->IrpThreads while another reads it. This vulnerability is fixed in 3.20.1.

Weakness: CWE-416 (Use After Free), CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-22856?

It affects 1 product.


Products: Freerdp Freerdp.

## How do I fix CVE-2026-22856?

Upgrade to a fixed version.

## Is CVE-2026-22856 being exploited?

There is no known exploitation of CVE-2026-22856 in the wild and no public exploit code.

## Other vulnerabilities in Freerdp Freerdp

- [CVE-2021-37594](https://insights.sbomify.com/CVE-2021-37594/): Other in n/a (critical 9.8)
- [CVE-2021-37595](https://insights.sbomify.com/CVE-2021-37595/): Other in n/a (critical 9.8)
- [CVE-2026-67305](https://insights.sbomify.com/CVE-2026-67305/): FreeRDP Windows Client before 3.29.0 Heap Buffer Overflow via Cliprdr (critical 9.4)
- [CVE-2026-66402](https://insights.sbomify.com/CVE-2026-66402/): FreeRDP before 3.29.0 TLS Certificate Identity Validation Bypass (critical 9.3)
- [CVE-2026-67289](https://insights.sbomify.com/CVE-2026-67289/): FreeRDP before 3.29.0 HTTP Proxy Request Injection via Redirection (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-22856 and fix it if it is affected.

What it is: CVE-2026-22856 is a medium-severity use after free vulnerability in Freerdp Freerdp, published on 14 Jan 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-22856 in the wild and no public exploit code.

Affected product: Freerdp Freerdp. 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-2026-22856/ (Markdown: https://insights.sbomify.com/CVE-2026-22856/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-22856
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-22856
- OSV: https://osv.dev/vulnerability/CVE-2026-22856

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-22856/
Summaries are generated and may contain mistakes; the official description above is the record.