Missing Authentication for Critical Function in FreeRDP - #VU164450
Published: November 10, 2026
Vulnerability identifier: #VU164450
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-306
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to inject keyboard and mouse input into the host user's interactive X11 session without authentication.
The vulnerability exists due to missing authentication checks in FreeRDP's fastpath_recv_input_event_* handlers in libfreerdp/core/fastpath.c when dispatching input before the session reaches CONNECTION_STATE_ACTIVE. A remote attacker can negotiate TLS-only RDP, withhold Confirm Active, and send crafted Fast-Path input PDUs to manipulate the host user's X11 session through XTEST.
Affected software
FreeRDP
Remediation
Install security update from vendor's website.
FreeRDP - update to 3.33.0