# CVE-2025-21225: Windows Remote Desktop Gateway (RD Gateway) Denial of Service Vulnerability

> Attackers can cause a denial of service in Windows Remote Desktop Gateway, requiring administrators to apply Microsoft security patches.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/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:** Not needed
- **Fix available:** No
- **Published:** 14 Jan 2025
- **Updated:** 9 Jun 2026
- **Also known as:** GHSA-qgf5-w7jw-p449

## What is CVE-2025-21225?

CVE-2025-21225 is a medium-severity denial of service vulnerability in Microsoft Windows Server 2016, published on 14 Jan 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Windows Remote Desktop Gateway (RD Gateway) Denial of Service Vulnerability

Weakness: CWE-843 (Access of Resource Using Incompatible Type)

## Which versions are affected by CVE-2025-21225?

It affects 5 products.


Products: Microsoft Windows Server 2016, Microsoft Windows Server 2019, Microsoft Windows Server 2022, Microsoft Windows Server 2022 23h2, Microsoft Windows Server 2025.

## How do I fix CVE-2025-21225?

No fix has been published for CVE-2025-21225 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-21225 being exploited?

There is no known exploitation of CVE-2025-21225 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft Windows Server 2016

- [CVE-2021-34458](https://insights.sbomify.com/CVE-2021-34458/): Windows Kernel Remote Code Execution Vulnerability (critical 9.9)
- [CVE-2024-38076](https://insights.sbomify.com/CVE-2024-38076/): Windows Remote Desktop Licensing Service Remote Code Execution Vulnerability (critical 9.8)
- [CVE-2026-27928](https://insights.sbomify.com/CVE-2026-27928/): Windows Hello Security Feature Bypass Vulnerability (high 8.7)
- [CVE-2025-27482](https://insights.sbomify.com/CVE-2025-27482/): Windows Remote Desktop Services Remote Code Execution Vulnerability (high 8.1)
- [CVE-2024-49106](https://insights.sbomify.com/CVE-2024-49106/): Windows Remote Desktop Services Remote Code Execution Vulnerability (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-21225 and fix it if it is affected.

What it is: CVE-2025-21225 is a medium-severity denial of service vulnerability in Microsoft Windows Server 2016, published on 14 Jan 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-21225 in the wild and no public exploit code.

Affected product: Microsoft Windows Server 2016. 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-2025-21225/ (Markdown: https://insights.sbomify.com/CVE-2025-21225/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-21225
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-21225
- OSV: https://osv.dev/vulnerability/CVE-2025-21225

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-21225/
Summaries are generated and may contain mistakes; the official description above is the record.