---
id: CVE-2026-91951
title: >-
  FreeRDP versions before 3.31.0 contain an out-of-bounds write vulnerability in
  the urbdrc client channel's urb_send_current_frame_number_result() function
summary: >-
  FreeRDP versions before 3.31.0 contain an out-of-bounds write vulnerability in
  the urbdrc client channel's urb_send_current_frame_number_result() function. A
  malicious RDP server can send a crafted 28-byte USB redirection message to
  trig…
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-617
  - CWE-787
vendor: freerdp
product: freerdp
affected:
  - 'freerdp >= 3.14.0, < 3.31.0'
patched:
  - freerdp 3.31.0
published: '2026-09-15'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T12:15:20.537'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91951'
references:
  - url: 'https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-h5w2-q35j-443h'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/freerdp-3.14.0-through-3.30.0-out-of-bounds-write-via-urbdrc
    label: disclosure@vulncheck.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91951.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-91951'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2533928'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-91951'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91951'
tags:
  - nvd
  - cve.org
  - exploit-available
  - csaf
  - vex
  - red-hat
epss: 0.0038
epssPercentile: 0.29308
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-20T00:28:36.418550Z'
ingestedAt: '2026-09-15T15:39:12.920Z'
---

## Overview

FreeRDP versions before 3.31.0 contain an out-of-bounds write vulnerability in the urbdrc client channel's urb_send_current_frame_number_result() function. A malicious RDP server can send a crafted 28-byte USB redirection message to trigger a 4-byte write past the allocated 16-byte buffer, causing denial of service when verbose asserts are enabled.

## Affected

- `freerdp >= 3.14.0, < 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 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91951.json)