Infinite loop in FreeRDP - CVE-2026-121959
Published: November 10, 2026 / Updated: November 11, 2026
Vulnerability identifier: #VU164433
CSH Severity: Medium
CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-121959
CWE-ID: CWE-835
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service by making a FreeRDP client thread consume CPU indefinitely.
The vulnerability exists due to an infinite loop in FreeRDP's websocket_context_read when a clean TLS EOF during an incomplete frame payload causes repeated zero-byte reads without state changes. A remote attacker can induce a client connection to a malicious RD Gateway, complete the WebSocket upgrade, send the truncated frame 82 05 68 65, and issue TLS close_notify to trigger persistent CPU consumption.
Affected software
FreeRDP
How to mitigate CVE-2026-121959
Install security update from vendor's website.
FreeRDP - update to 3.32.2