# CVE-2026-110839: FreeRDP 3.3.0 before 3.32.0 Heap Out-of-Bounds Write via Grayscale JPEG Clipboard Data

> A malicious RDP server can trigger a heap out-of-bounds write in FreeRDP clients via grayscale JPEG clipboard data, causing crashes or potential code execution.

- **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:H/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:** 14 Oct 2026
- **Updated:** 15 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-110839, GHSA-2hqx-8xx3-ffcj, GHSA-99p4-8j24-wvj4, UBUNTU-CVE-2026-110839

## What is CVE-2026-110839?

CVE-2026-110839 is a high-severity memory corruption vulnerability in Freerdp Freerdp, published on 14 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

FreeRDP 3.3.0 before 3.32.0, when built with WINPR_UTILS_IMAGE_JPEG=ON, has a heap-based out-of-bounds write in winpr_convert_from_jpeg because grayscale JPEG buffers are sized from one input component rather than three BGR output components. A malicious RDP server can offer a grayscale JPEG via clipboard redirection, corrupting client memory and crashing it when the item is pasted as CF_DIB bitmap data.

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

## Which versions are affected by CVE-2026-110839?

It affects 1 product.


Products: Freerdp Freerdp.

## How do I fix CVE-2026-110839?

Upgrade to a fixed version.

## Is CVE-2026-110839 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-110839 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-2026-110839 and fix it if it is affected.

What it is: CVE-2026-110839 is a high-severity memory corruption vulnerability in Freerdp Freerdp, published on 14 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-2026-110839 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-2026-110839/ (Markdown: https://insights.sbomify.com/CVE-2026-110839/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-110839
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-110839
- OSV: https://osv.dev/vulnerability/CVE-2026-110839

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-110839/
Summaries are generated and may contain mistakes; the official description above is the record.