CVE-2026-91949
criticalFreeRDP server versions before 3.31.0 contain a protocol negotiation bypass vulnerability that allows unauthenticated attackers to establish RDSTLS connections…
Vendor / product: Freerdp — freerdp
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
9.3
9.3 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N Severity source: NVD CVSS v3.1 (disclosure@vulncheck.com)
Timeline (UTC)
Published: 2026-09-15 16:17
Modified: 2026-09-24 12:14
NVD status: Analyzed
Last synced 1 day ago
Verified against the source API 2026-10-27 06:53 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
freerdp / freerdp ≥3.0.0 <3.31.0
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
Patch / mitigation: https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-x7v6-xfx3-52j6
References
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-x7v6-xfx3-52j6 disclosure@vulncheck.com
- https://www.vulncheck.com/advisories/freerdp-3.0.0-through-3.30.0-protocol-negotiation-byp... disclosure@vulncheck.com
Data sources
NVD CVE API 2.0 — fetched 2026-10-27 06:53 UTC · record ↗