---
id: CVE-2026-91964
title: >-
  FreeRDP versions before 3.31.0 contain a heap-based buffer overflow in
  nego_send_negotiation_request when processing Server Redirection PDU messages
  with attacker-controlled LoadBalanceInfo fields
summary: >-
  FreeRDP versions before 3.31.0 contain a heap-based buffer overflow in
  nego_send_negotiation_request when processing Server Redirection PDU messages
  with attacker-controlled LoadBalanceInfo fields. A malicious RDP server can
  trigger the …
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cwe:
  - CWE-122
  - CWE-120
vendor: FreeRDP
product: FreeRDP
affected:
  - FreeRDP >= 2.0.0 < 3.0.0
  - FreeRDP >= 3.0.0 < 3.31.0
  - FreeRDP < 3.31.0
published: '2026-09-15'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T20:44:42.207'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91964'
references:
  - url: 'https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-2vf2-grvj-6g8x'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/freerdp-2.0.0-through-3.30.0-heap-buffer-overflow-via-routingtoken
    label: disclosure@vulncheck.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91964.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-91964'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2533911'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-91964'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91964'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00599
epssPercentile: 0.46396
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-16T03:56:32.717523Z'
ingestedAt: '2026-09-15T15:39:12.915Z'
---

## Overview

FreeRDP versions before 3.31.0 contain a heap-based buffer overflow in nego_send_negotiation_request when processing Server Redirection PDU messages with attacker-controlled LoadBalanceInfo fields. A malicious RDP server can trigger the overflow by sending an arbitrary-length field that gets written to a fixed 512-byte buffer without validation, causing client crashes or potential code execution when chained with memory disclosure.

## 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-2026-91964.json)