# CVE-2026-67305: FreeRDP Windows Client before 3.29.0 Heap Buffer Overflow via Cliprdr

> A malicious RDP server can trigger a heap buffer overflow in the FreeRDP Windows client, potentially enabling remote code execution during paste operations.

- **Severity:** Critical 9.4 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`)
- **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:** 1 Aug 2026
- **Updated:** 5 Aug 2026
- **Also known as:** GHSA-3w26-2cxg-pvh3, GHSA-cj9v-h4hq-29jr

## What is CVE-2026-67305?

CVE-2026-67305 is a critical memory corruption vulnerability in Freerdp Freerdp, published on 1 Aug 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 Windows client before 3.29.0 contains a heap buffer overflow vulnerability in the clipboard virtual channel when processing CLIPRDR_FILE_CONTENTS_RESPONSE PDUs without validating the server-provided size against the destination buffer. A malicious RDP server can send a response with a data payload significantly larger than requested, causing arbitrary heap memory corruption that may enable remote code execution when a user performs a paste operation.

Weakness: CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-67305?

It affects 1 product.


Products: Freerdp Freerdp.

## How do I fix CVE-2026-67305?

No fix has been published for CVE-2026-67305 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-67305 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-67305 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-2026-66402](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)
- [CVE-2026-67292](https://insights.sbomify.com/CVE-2026-67292/): FreeRDP before 3.29.0 WebSocket Ping Buffer Over-disclosure (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-67305 and fix it if it is affected.

What it is: CVE-2026-67305 is a critical memory corruption vulnerability in Freerdp Freerdp, published on 1 Aug 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-2026-67305 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-2026-67305/ (Markdown: https://insights.sbomify.com/CVE-2026-67305/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-67305
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-67305
- OSV: https://osv.dev/vulnerability/CVE-2026-67305

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-67305/
Summaries are generated and may contain mistakes; the official description above is the record.