# CVE-2026-109951: FreeRDP 3.17.1 before 3.32.0 Heap Buffer Over-Read via Proxy DRDYNVC Channel Name

> A heap buffer over-read in FreeRDP allows malicious RDP servers to leak memory or crash the proxy via malformed channel names.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Oct 2026
- **Updated:** 18 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-109951, GHSA-g4wg-67xq-8q53, GHSA-h552-rp6x-j2cx, UBUNTU-CVE-2026-109951

## What is CVE-2026-109951?

CVE-2026-109951 is a medium-severity vulnerability in Freerdp Freerdp, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

FreeRDP 3.17.1 before 3.32.0 contains a heap buffer over-read vulnerability in DynvcTrackerHandleCreateBack of the freerdp-proxy DRDYNVC channel handler that allows malicious backend RDP servers to read heap memory out of bounds. Attackers can send a CREATE_REQUEST_PDU whose channel name lacks a NUL byte, causing an unbounded snprintf read that leaks memory into proxy logs or crashes the process.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-109951?

It affects 1 product.


Products: Freerdp Freerdp.

## How do I fix CVE-2026-109951?

Upgrade to a fixed version.

## Is CVE-2026-109951 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-109951 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-2026-109951 and fix it if it is affected.

What it is: CVE-2026-109951 is a medium-severity vulnerability in Freerdp Freerdp, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-109951 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-2026-109951/ (Markdown: https://insights.sbomify.com/CVE-2026-109951/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-109951
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-109951
- OSV: https://osv.dev/vulnerability/CVE-2026-109951

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-109951/
Summaries are generated and may contain mistakes; the official description above is the record.