---
id: CVE-2026-109240
title: >-
  FreeRDP 3.11.0 before 3.32.1 contains a reachable assertion vulnerability in
  urb_isoch_transfer that allows malicious RDP servers to crash clients by
  sending unvalidated OutputBufferSize values
summary: >-
  FreeRDP 3.11.0 before 3.32.1 contains a reachable assertion vulnerability in
  urb_isoch_transfer that allows malicious RDP servers to crash clients by
  sending unvalidated OutputBufferSize values. Attackers can send a
  TS_URB_ISOCH_TRANSFER…
severity: low
cvss: 3.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L'
cwe:
  - CWE-617
vendor: Red Hat
product: Red Hat Enterprise Linux 10
affected:
  - enterprise_linux 10
published: '2026-10-12'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T20:11:45.520'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-109240'
references:
  - url: 'https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9qqc-m43j-g4r2'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/freerdp-3.11.0-before-3.32.1-reachable-assertion-dos-via-urb-isoch-transfer
    label: disclosure@vulncheck.com
  - url: 'https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-9qqc-m43j-g4r2'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-109240.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-109240'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2549780'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-109240'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-109240'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
  - cve.org
  - exploit-available
epss: 0.00265
epssPercentile: 0.18296
ingestedAt: '2026-10-12T18:00:08.172Z'
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-13T17:59:52.016134Z'
---

## Overview

FreeRDP 3.11.0 before 3.32.1 contains a reachable assertion vulnerability in urb_isoch_transfer that allows malicious RDP servers to crash clients by sending unvalidated OutputBufferSize values. Attackers can send a TS_URB_ISOCH_TRANSFER IN-direction request with OutputBufferSize above INT32_MAX over URBDRC, triggering an assertion in libusb_udev_isoch_transfer that terminates the client.

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-10-13 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-109240.json)