Reachable assertion in FreeRDP - #VU156161
Published: October 19, 2026
Vulnerability identifier: #VU156161
CSH Severity: Low
CVSS v4: 1.8 [CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-617
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 triggering an assertion that aborts an X11 FreeRDP client.
The vulnerability exists due to insufficient validation of server-supplied scaled-output geometry in FreeRDP's RDPGFX and X11 graphics handling when processing surface mappings and subsequent display updates. A remote attacker can induce a victim to connect to a controlled RDP server, create a graphics surface, and send a MAPSURFACETOSCALEDOUTPUT PDU with oversized target dimensions or output coordinates to trigger a checked-cast or scaling assertion under the affected rendering conditions.
Affected software
FreeRDP
Remediation
Install security update from vendor's website.
FreeRDP - update to 3.32.2