# CVE-2026-121952: FreeRDP before 3.32.2 Proxy Out-of-Bounds Write via Bitmap Cache v2 Capability


- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 4 Nov 2026
- **Updated:** 4 Nov 2026
- **Also known as:** DEBIAN-CVE-2026-121952, GHSA-9gqr-m6pm-p7q7, GHSA-xc85-4mqc-xgcx, UBUNTU-CVE-2026-121952

## What is CVE-2026-121952?

CVE-2026-121952 is a critical vulnerability in FreeRDP, published on 4 Nov 2026. 

### Official description

FreeRDP before 3.32.2 has an out-of-bounds write in the proxy because rdp_read_bitmap_cache_v2_capability_set rejects only numCellCaches values above 5, yet the bitmap cache v2 cell array is later accessed at fixed indices 0 through 4. A client connecting to the proxy can declare fewer than five cell caches in its Confirm Active, causing heap corruption, heap data leakage to the backend, or a crash.

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

## Which versions are affected by CVE-2026-121952?

It affects 1 product.


Products: FreeRDP.

## How do I fix CVE-2026-121952?

Upgrade to a fixed version.

## Is CVE-2026-121952 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-121952 exists.

## Other vulnerabilities in FreeRDP

- [CVE-2024-32658](https://insights.sbomify.com/CVE-2024-32658/): FreeRDP ExtractRunLengthRegular* out of bound read (critical 9.8)
- [CVE-2024-32659](https://insights.sbomify.com/CVE-2024-32659/): freerdp_image_copy out of bound read (critical 9.8)
- [CVE-2024-32039](https://insights.sbomify.com/CVE-2024-32039/): FreeRDP Integer overflow & OutOfBound Write in clear_decompress_residual_data (critical 9.8)
- [CVE-2024-32041](https://insights.sbomify.com/CVE-2024-32041/): FreeRDP OutOfBound Read in zgfx_decompress_segment (critical 9.8)
- [CVE-2024-32458](https://insights.sbomify.com/CVE-2024-32458/): FreeRDP Out-Of-Bounds Read in planar_skip_plane_rle (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-121952 and fix it if it is affected.

What it is: CVE-2026-121952 is a critical vulnerability in FreeRDP, published on 4 Nov 2026. 
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-121952 exists.

Affected product: 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-2026-121952/ (Markdown: https://insights.sbomify.com/CVE-2026-121952/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-121952
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-121952
- OSV: https://osv.dev/vulnerability/CVE-2026-121952

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-121952/
Summaries are generated and may contain mistakes; the official description above is the record.