The FreeRDP client 3.0.0 before 3.32.0 does not check a server-selected PROTOCOL_RDSTLS or PROTOCOL_HYBRID_EX against its enabled protocol set in nego_process_negotiation_response(), allowing a security protocol downgrade. A malicious server or man-in-the-middle can select RDSTLS to override /sec:nla pinning, complete authentication with an all-zero cookie, and receive the user's cleartext password in the Client Info PDU.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-qq23-mqmv-pc65 Exploit, Vendor Advisory
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-qq23-mqmv-pc65 Exploit, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 4
- Cpes+1 CPE criteria (now 1)NVD modified 2026-10-21 14:16
- StatusUndergoing Analysis → AnalyzedNVD modified 2026-10-21 14:16
- StatusAwaiting Analysis → Undergoing AnalysisNVD modified 2026-10-16 22:17
- First seenCVSS 6.0NVD modified 2026-10-14 20:10
Affected (CPE criteria) 1
cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*
References 3
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-qq23-mqmv-pc65 Exploit, Vendor Advisory
- https://www.vulncheck.com/advisories/freerdp-3.0.0-before-3.32.0-security-protocol-downgrade-via-negotiation-response Third Party Advisory
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-qq23-mqmv-pc65 Exploit, Vendor Advisory