# CVE-2026-109952: FreeRDP 3.0.0 before 3.32.0 Security Protocol Downgrade via Negotiation Response

> A malicious server or man-in-the-middle can downgrade security protocols to bypass NLA pinning and capture cleartext passwords from FreeRDP clients.

- **Severity:** Medium 6.0 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **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:** 13 Oct 2026
- **Updated:** 16 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-109952, GHSA-c6qf-gf3v-f99j, GHSA-qq23-mqmv-pc65, UBUNTU-CVE-2026-109952

## What is CVE-2026-109952?

CVE-2026-109952 is a medium-severity vulnerability in Freerdp Freerdp, published on 13 Oct 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

The FreeRDP client 3.0.0 before 3.32.0 does not check a server-selected PROTOCOL_RDSTLS or PROTOCOL_HYBRID_EX against its enabled protocol set in nego_process_negotiation_response(), allowing a security protocol downgrade. A malicious server or man-in-the-middle can select RDSTLS to override /sec:nla pinning, complete authentication with an all-zero cookie, and receive the user's cleartext password in the Client Info PDU.

Weakness: CWE-757 (Selection of Less-Secure Algorithm During Negotiation)

## Which versions are affected by CVE-2026-109952?

It affects 1 product.


Products: Freerdp Freerdp.

## How do I fix CVE-2026-109952?

Upgrade to a fixed version.

## Is CVE-2026-109952 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-109952 exists.

## 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-2026-109952 and fix it if it is affected.

What it is: CVE-2026-109952 is a medium-severity vulnerability in Freerdp Freerdp, published on 13 Oct 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: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-109952 exists.

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-2026-109952/ (Markdown: https://insights.sbomify.com/CVE-2026-109952/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-109952
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-109952
- OSV: https://osv.dev/vulnerability/CVE-2026-109952

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-109952/
Summaries are generated and may contain mistakes; the official description above is the record.