# CVE-2026-42913: Remote Desktop Client Remote Code Execution Vulnerability

> An attacker can execute arbitrary code remotely via a race condition in the Microsoft Remote Desktop Client.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C`)
- **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:** No
- **Published:** 9 Jun 2026
- **Updated:** 24 Sep 2026
- **Also known as:** GHSA-m239-3rrf-2x78

## What is CVE-2026-42913?

CVE-2026-42913 is a high-severity vulnerability in Microsoft Windows 11 23h2, published on 9 Jun 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

Concurrent execution using shared resource with improper synchronization ('race condition') in Remote Desktop Client allows an unauthorized attacker to execute code over a network.

Weakness: CWE-787 (Out-of-bounds Write), CWE-416 (Use After Free), CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-42913?

It affects 7 products.


Products: Microsoft Remote Desktop Client, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2, Microsoft Windows 11 26h1, Microsoft Windows Server 2022, Microsoft Windows Server 2025.

## How do I fix CVE-2026-42913?

No fix has been published for CVE-2026-42913 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-42913 being exploited?

There is no known exploitation of CVE-2026-42913 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft Windows 11 23h2

- [CVE-2026-78463](https://insights.sbomify.com/CVE-2026-78463/): Remote Desktop Client Remote Code Execution Vulnerability (high 8.8)
- [CVE-2026-80074](https://insights.sbomify.com/CVE-2026-80074/): Remote Desktop Client Remote Code Execution Vulnerability (high 8.8)
- [CVE-2026-80077](https://insights.sbomify.com/CVE-2026-80077/): Remote Desktop Client Remote Code Execution Vulnerability (high 8.8)
- [CVE-2026-42985](https://insights.sbomify.com/CVE-2026-42985/): Remote Desktop Client Remote Code Execution Vulnerability (high 8.8)
- [CVE-2026-32157](https://insights.sbomify.com/CVE-2026-32157/): Remote Desktop Client Remote Code Execution Vulnerability (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-42913 and fix it if it is affected.

What it is: CVE-2026-42913 is a high-severity vulnerability in Microsoft Windows 11 23h2, published on 9 Jun 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-2026-42913 in the wild and no public exploit code.

Affected product: Microsoft Windows 11 23h2. 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-2026-42913/ (Markdown: https://insights.sbomify.com/CVE-2026-42913/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42913
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42913
- OSV: https://osv.dev/vulnerability/CVE-2026-42913

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-42913/
Summaries are generated and may contain mistakes; the official description above is the record.