Reachable assertion in FreeRDP - #VU137830
Published: July 16, 2026
Vulnerability identifier: #VU137830
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/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.
The vulnerability exists due to an assertion failure caused by improper handling of zero-length ping control frames in the gateway WebSocket transport when processing server-sent ping control frames. A remote attacker can send a zero-length ping frame to cause a denial of service.
A valid zero-length Ping reaches an assertion in websocket_context_write_wstream() and terminates the client.
Affected software
FreeRDP
Remediation
Install security update from vendor's website.
FreeRDP - update to 3.29.0