Infinite loop in FreeRDP - CVE-2026-121404
Published: November 10, 2026 / Updated: November 11, 2026
Vulnerability identifier: #VU164435
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-121404
CWE-ID: CWE-835
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service through sustained CPU consumption on a FreeRDP shadow server.
The vulnerability exists due to a loop with an unreachable exit condition in channel readers when FreeRDP_WTSVirtualChannelRead length queries leave zero-byte messages queued and queue events signaled. A remote user can send zero-payload drdynvc DATA messages to opened audin or negotiated rdpgfx channels, or exploit the related joined encomsp static-channel variant, to trigger continuous thread spinning until disconnection.
Affected software
FreeRDP
How to mitigate CVE-2026-121404
Install security update from vendor's website.
FreeRDP - update to 3.32.2