CVE-2026-91949: Freerdp

Critical severity, CVSS 9.3. EPSS: 0.6% chance of exploitation in the next 30 days.

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.

Affected products

• Freerdp Freerdp: from 3.0.0, before 3.31.0 (fixed in 3.31.0)

Published 2026-09-15. Last modified 2026-09-24.