---
id: CVE-2026-55192
title: FreeRDP is a free implementation of the Remote Desktop Protocol
summary: >-
  FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to
  3.27.0, FreeRDP H.264 decoder backends can return YUV planes sized from the
  bitstream without comparing the decoded width and height to the RDPGFX surface
  dimensio…
severity: high
cvss: 8.2
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H'
cwe:
  - CWE-125
vendor: freerdp
product: freerdp
affected:
  - freerdp < 3.27.0
patched:
  - freerdp 3.27.0
published: '2026-08-19'
updated: '2026-09-22'
sourceUpdated: '2026-09-22T19:45:48.113'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55192'
references:
  - url: >-
      https://github.com/FreeRDP/FreeRDP/commit/0cd45b70bb1fe6befd258ff64c46461947e99adb
    label: security-advisories@github.com
  - url: 'https://github.com/FreeRDP/FreeRDP/pull/12873'
    label: security-advisories@github.com
  - url: 'https://github.com/FreeRDP/FreeRDP/releases/tag/3.27.0'
    label: security-advisories@github.com
  - url: 'https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-3mmf-qh4f-frm6'
    label: security-advisories@github.com
  - url: 'https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-3mmf-qh4f-frm6'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-55192.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-55192'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2519823'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-55192'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55192'
  - url: 'https://access.redhat.com/errata/RHSA-2026:68707'
  - url: 'https://access.redhat.com/errata/RHSA-2026:68706'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
epss: 0.00462
epssPercentile: 0.39297
scores:
  nvd: 8.2
  vendor: 8.1
ingestedAt: '2026-09-09T21:22:45.541Z'
---

## Overview

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, FreeRDP H.264 decoder backends can return YUV planes sized from the bitstream without comparing the decoded width and height to the RDPGFX surface dimensions used to validate region rectangles. A malicious RDP server can provide an AVC420 or AVC444 bitstream whose decoded frame is smaller than the negotiated surface, causing yuv420_context_decode and the YUV-to-RGB conversion paths to read beyond the decoder-owned planes in libfreerdp/codec/h264.c and the selected H.264 backend. This can disclose client memory or crash the client. This issue is fixed in version 3.27.0.

## Affected

- `freerdp < 3.27.0`

## Remediation

Upgrade past the affected range:

- `freerdp 3.27.0`

## Vendor advisories

- **RHSA-2026:68707** · Red Hat · fixed in: Red Hat Enterprise Linux Server (v. 7 ELS), Red Hat Enterprise Linux Server Optional (v. 7 ELS) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68707)
- **RHSA-2026:68706** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) · released 2026-09-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:68706)
- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-09-22 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-55192.json)