---
id: CVE-2026-91963
title: >-
  FreeRDP versions before 3.31.0 contain an uninitialized heap memory disclosure
  vulnerability in the urbdrc USB redirection channel
summary: >-
  FreeRDP versions before 3.31.0 contain an uninitialized heap memory disclosure
  vulnerability in the urbdrc USB redirection channel. A malicious RDP server
  can induce failing USB transfers to read uninitialized heap memory from the
  client…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N'
cwe:
  - CWE-457
  - CWE-824
vendor: freerdp
product: freerdp
affected:
  - 'freerdp >= 2.0.0, < 3.31.0'
patched:
  - freerdp 3.31.0
published: '2026-09-15'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T20:08:36.160'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91963'
references:
  - url: 'https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-hw7p-5h2r-83gq'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/freerdp-2.0.0-through-3.30.0-uninitialized-heap-memory-disclosure-via-urbdrc
    label: disclosure@vulncheck.com
  - url: 'https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-hw7p-5h2r-83gq'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91963.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-91963'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2533930'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-91963'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91963'
tags:
  - nvd
  - cve.org
  - exploit-available
  - csaf
  - vex
  - red-hat
  - score-dispute
epss: 0.0064
epssPercentile: 0.49277
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-15T15:56:52.431518Z'
scores:
  nvd: 6.5
  vendor: 8.8
ingestedAt: '2026-09-15T15:39:12.916Z'
---

## Overview

FreeRDP versions before 3.31.0 contain an uninitialized heap memory disclosure vulnerability in the urbdrc USB redirection channel. A malicious RDP server can induce failing USB transfers to read uninitialized heap memory from the client, defeating ASLR and enabling remote code execution when chained with memory corruption vulnerabilities.

## Affected

- `freerdp >= 2.0.0, < 3.31.0`

## Remediation

Upgrade past the affected range:

- `freerdp 3.31.0`

## 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-2026-91963.json)