CVE-2026-91949: freerdp freerdp

CVSS 9.3 (critical) · published 2026-09-15

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 (NVD): freerdp freerdp

Fixed in (NVD): 3.31.0

Weakness: CWE-693

Source: NVD CVE-2026-91949

References

• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-x7v6-xfx3-52j6
• https://www.vulncheck.com/advisories/freerdp-3.0.0-through-3.30.0-protocol-negotiation-bypass

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