Reachable assertion in FreeRDP - #VU146587
Published: September 1, 2026
Vulnerability identifier: #VU146587
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/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.
The vulnerability exists due to reachable assertion in rdp_write_multifragment_update_capability_set when processing client-supplied DesktopWidth and DesktopHeight values during GCC negotiation and Demand Active capability writing. A remote attacker can send specially crafted desktop dimension values to cause a denial of service.
In the verified TLS-only or standard RDP security configuration without NLA, the crash occurs before credential verification. Default-build configurations with verbose assertions enabled are affected.
Affected software
FreeRDP
Remediation
Install security update from vendor's website.
FreeRDP - update to 3.31.0