---
id: CVE-2026-91960
title: >-
  FreeRDP versions before 3.31.0 contain an integer overflow in WinPR's
  Stream_EnsureRemainingCapacity function that allows remote attackers to cause
  denial of service
summary: >-
  FreeRDP versions before 3.31.0 contain an integer overflow in WinPR's
  Stream_EnsureRemainingCapacity function that allows remote attackers to cause
  denial of service. A malicious RD Gateway peer can send a WebSocket Ping frame
  with a cra…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'
cwe:
  - CWE-190
vendor: freerdp
product: freerdp
affected:
  - freerdp < 3.31.0
patched:
  - freerdp 3.31.0
published: '2026-09-15'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T12:17:24.547'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91960'
references:
  - url: 'https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vccg-35r5-8jrf'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/freerdp-before-3.31.0-integer-overflow-double-free
    label: disclosure@vulncheck.com
  - url: 'https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vccg-35r5-8jrf'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91960.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-91960'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2533957'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-91960'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91960'
tags:
  - nvd
  - cve.org
  - exploit-available
  - csaf
  - vex
  - red-hat
epss: 0.00438
epssPercentile: 0.35339
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-15T15:55:16.546099Z'
ingestedAt: '2026-09-15T15:39:12.916Z'
---

## Overview

FreeRDP versions before 3.31.0 contain an integer overflow in WinPR's Stream_EnsureRemainingCapacity function that allows remote attackers to cause denial of service. A malicious RD Gateway peer can send a WebSocket Ping frame with a crafted 64-bit extended payload length to trigger integer wraparound, resulting in a double free that crashes the FreeRDP client during connection.

## Affected

- `freerdp < 3.31.0`

## Remediation

Upgrade past the affected range:

- `freerdp 3.31.0`

## Vendor advisories

- **Red Hat VEX** · Moderate · 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-2026-91960.json)