---
id: CVE-2026-91955
title: >-
  FreeRDP before 3.31.0 fails to validate client-supplied DesktopWidth and
  DesktopHeight values during GCC negotiation, allowing remote attackers to
  crash the server
summary: >-
  FreeRDP before 3.31.0 fails to validate client-supplied DesktopWidth and
  DesktopHeight values during GCC negotiation, allowing remote attackers to
  crash the server. Attackers can send crafted RDP packets with zero or
  oversized dimensions…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-369
vendor: FreeRDP
product: FreeRDP
affected:
  - FreeRDP < 3.31.0
published: '2026-09-15'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T20:15:36.037'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91955'
references:
  - url: 'https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-4464-r7qj-pgrx'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/freerdp-before-3.31.0-denial-of-service-via-desktop-dimensions
    label: disclosure@vulncheck.com
  - url: 'https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-4464-r7qj-pgrx'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91955.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-91955'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2533907'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-91955'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91955'
tags:
  - nvd
  - cve.org
  - exploit-available
  - csaf
  - vex
  - red-hat
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-15T15:54:25.986513Z'
ingestedAt: '2026-09-15T15:39:12.919Z'
epss: 0.00452
epssPercentile: 0.38509
---

## Overview

FreeRDP before 3.31.0 fails to validate client-supplied DesktopWidth and DesktopHeight values during GCC negotiation, allowing remote attackers to crash the server. Attackers can send crafted RDP packets with zero or oversized dimensions to trigger division-by-zero or assertion failures in multifragment update capability calculations, terminating the server process.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91955.json)