CVE-2026-91953

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.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-r9pv-ffph-6gg6	Exploit Mitigation Vendor Advisory
https://www.vulncheck.com/advisories/freerdp-before-3.31.0-heap-buffer-overflow-via-lb-load-balance-info	Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*

History

24 Sep 2026, 12:16

Type	Values Removed	Values Added
First Time		Freerdp freerdp Freerdp
CPE		cpe:2.3:a:freerdp:freerdp::::::::
References	~~() https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-r9pv-ffph-6gg6 -~~	() https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-r9pv-ffph-6gg6 - Exploit, Mitigation, Vendor Advisory
References	~~() https://www.vulncheck.com/advisories/freerdp-before-3.31.0-heap-buffer-overflow-via-lb-load-balance-info -~~	() https://www.vulncheck.com/advisories/freerdp-before-3.31.0-heap-buffer-overflow-via-lb-load-balance-info - Third Party Advisory

Information

Published : 2026-09-15 16:17

Updated : 2026-09-24 12:16

NVD link : CVE-2026-91953

Mitre link : CVE-2026-91953

CVE.ORG link : CVE-2026-91953

JSON object : View

Products Affected

freerdp

freerdp

CWE

CWE-120

Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

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