---
title: "CVE-2026-26955\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2026-26955?format=md
keywords: index, follow
---

# CVE-2026-26955

Publication date 25 February 2026

Last updated 18 March 2026

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**8.8 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2026-26955?format=md#impact-score)

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## Description

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to
version 3.23.0, a malicious RDP server can trigger a heap buffer overflow
in FreeRDP clients using the GDI surface pipeline (e.g., `xfreerdp`) by
sending an RDPGFX ClearCodec surface command with an out-of-bounds
destination rectangle. The `gdi\_SurfaceCommand\_ClearCodec()` handler does
not call `is\_within\_surface()` to validate the command rectangle against
the destination surface dimensions, allowing attacker-controlled
`cmd->left`/`cmd->top` (and subcodec rectangle offsets) to reach image copy
routines that write into `surface->data` without bounds enforcement. The
OOB write corrupts an adjacent `gdiGfxSurface` struct's `codecs\*` pointer
with attacker-controlled pixel data, and corruption of `codecs\*` is
sufficient to reach an indirect function pointer call (`NSC\_CONTEXT.decode`
at `nsc.c:500`) on a subsequent codec command — full instruction pointer
(RIP) control demonstrated in exploitability harness. Users should upgrade
to version 3.23.0 to receive a patch.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| freerdp | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release |
| 24.04 LTS noble | Not in release |
| 22.04 LTS jammy | Not in release |
| 18.04 LTS bionic | Needs evaluation |
| 16.04 LTS xenial | Needs evaluation |
| freerdp2 | 26.04 LTS resolute | Not in release |
| 25.10 questing | Not in release |
| 24.04 LTS noble | Needs evaluation |
| 22.04 LTS jammy | Needs evaluation |
| 20.04 LTS focal | Needs evaluation |
| 18.04 LTS bionic | Needs evaluation |
| freerdp3 | 26.04 LTS resolute | Not affected |
| 25.10 questing | Fixed 3.16.0+dfsg-2ubuntu0.3 |
| 24.04 LTS noble | Fixed 3.5.1+dfsg1-0ubuntu1.4 |
| 22.04 LTS jammy | Not in release |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)
* [Patch details](https://ubuntu.com/security/CVE-2026-26955?format=md#patch-details)

### Patch details

For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)

| Package | Patch details |
| --- | --- |
| freerdp3 | * Upstream:   [7d8fdce](https://github.com/FreeRDP/FreeRDP/commit/7d8fdce2d0ef337cb86cb37fc0c436c905e04d77) |

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

8.8 · High

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | Low |
  | Privileges required | None |
  | User interaction | Required |
  | Scope | Unchanged |
  | Confidentiality impact | High |
  | Integrity impact | High |
  | Availability impact | High |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 8.8 · High |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-26955)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2026-26955)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2026-26955)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2026-26955)

### Related Ubuntu Security Notices (USN)

+ [USN-8105-1](https://usn.ubuntu.com/USN-8105-1)
+ FreeRDP vulnerabilities
+ 18 March 2026

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2026-26955>
* <https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-mr6w-ch7c-mqqj>