FreeRDP versions before 3.31.0 contain a heap buffer overflow vulnerability in nego_send_negotiation_request() that fails to validate the LB_LOAD_BALANCE_INFO field length before writing to a fixed 512-byte buffer. A malicious RDP server or man-in-the-middle can send a Server Redirection PDU with an oversized LB_LOAD_BALANCE_INFO value to overflow the buffer with attacker-controlled content, causing denial of service or heap corruption before authentication completes.
History

Wed, 16 Sep 2026 12:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 16 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


Tue, 15 Sep 2026 15:30:00 +0000

Type Values Removed Values Added
Description FreeRDP versions before 3.31.0 contain a heap buffer overflow vulnerability in nego_send_negotiation_request() that fails to validate the LB_LOAD_BALANCE_INFO field length before writing to a fixed 512-byte buffer. A malicious RDP server or man-in-the-middle can send a Server Redirection PDU with an oversized LB_LOAD_BALANCE_INFO value to overflow the buffer with attacker-controlled content, causing denial of service or heap corruption before authentication completes.
Title FreeRDP before 3.31.0 Heap Buffer Overflow via LB_LOAD_BALANCE_INFO
First Time appeared Freerdp
Freerdp freerdp
Weaknesses CWE-120
CPEs cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*
Vendors & Products Freerdp
Freerdp freerdp
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-09-15T15:18:09.893Z

Updated: 2026-09-15T16:01:36.361Z

Reserved: 2026-09-15T11:07:34.398Z

Link: CVE-2026-91953

cve-icon Vulnrichment

Updated: 2026-09-15T16:01:23.826Z

cve-icon NVD

Status : Analyzed

Published: 2026-09-15T16:17:49.657

Modified: 2026-09-24T12:16:27.010

Link: CVE-2026-91953

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-09-15T15:18:09Z

Links: CVE-2026-91953 - Bugzilla