CVE-2026-91949

FreeRDP server versions before 3.31.0 contain a protocol negotiation bypass vulnerability that allows unauthenticated attackers to establish RDSTLS connections despite server policy disabling them. Attackers can send incompatible protocol requests, receive negotiation failures, then complete TLS handshake and enter RDSTLS to bypass pre-authentication transport restrictions.

CVSS v3 9.3 CRITICAL

9.3^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 4.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-x7v6-xfx3-52j6	Exploit Mitigation Vendor Advisory
https://www.vulncheck.com/advisories/freerdp-3.0.0-through-3.30.0-protocol-negotiation-bypass	Third Party Advisory

Configurations

Configuration 1 (hide)

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

History

24 Sep 2026, 12:14

Type	Values Removed	Values Added
CPE		cpe:2.3:a:freerdp:freerdp::::::::
First Time		Freerdp freerdp Freerdp
References	~~() https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-x7v6-xfx3-52j6 -~~	() https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-x7v6-xfx3-52j6 - Exploit, Mitigation, Vendor Advisory
References	~~() https://www.vulncheck.com/advisories/freerdp-3.0.0-through-3.30.0-protocol-negotiation-bypass -~~	() https://www.vulncheck.com/advisories/freerdp-3.0.0-through-3.30.0-protocol-negotiation-bypass - Third Party Advisory

Information

Published : 2026-09-15 16:17

Updated : 2026-09-24 12:14

NVD link : CVE-2026-91949

Mitre link : CVE-2026-91949

CVE.ORG link : CVE-2026-91949

JSON object : View

Products Affected

freerdp

freerdp

CWE

CWE-693

Protection Mechanism Failure

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