# CVE-2026-29775: FreeRDP has a heap-buffer-overflow in bitmap_cache_put via OOB cacheId

> A malicious RDP server can trigger a heap buffer overflow in the FreeRDP client, potentially leading to code execution or denial of service.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Mar 2026
- **Updated:** 16 Mar 2026
- **Also known as:** DEBIAN-CVE-2026-29775, GHSA-h666-rfw3-jhvj, UBUNTU-CVE-2026-29775

## What is CVE-2026-29775?

CVE-2026-29775 is a medium-severity memory corruption vulnerability in Freerdp Freerdp, published on 13 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a client-side heap out-of-bounds read/write occurs in FreeRDP's bitmap cache subsystem due to an off-by-one boundary check in bitmap_cache_put. A malicious server can send a CACHE_BITMAP_ORDER (Rev1) with cacheId equal to maxCells, bypassing the guard and accessing cells[] one element past the allocated array. This vulnerability is fixed in 3.24.0.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-29775?

It affects 1 product.


Products: Freerdp Freerdp.

## How do I fix CVE-2026-29775?

Upgrade to a fixed version.

## Is CVE-2026-29775 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-29775 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-2026-29775 and fix it if it is affected.

What it is: CVE-2026-29775 is a medium-severity memory corruption vulnerability in Freerdp Freerdp, published on 13 Mar 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-2026-29775 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-2026-29775/ (Markdown: https://insights.sbomify.com/CVE-2026-29775/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-29775
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-29775
- OSV: https://osv.dev/vulnerability/CVE-2026-29775

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-29775/
Summaries are generated and may contain mistakes; the official description above is the record.