Reachable assertion in FreeRDP - #VU156162
Published: October 19, 2026
Vulnerability identifier: #VU156162
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 terminating an assertion-enabled FreeRDP client.
The vulnerability exists due to a reachable assertion in update_process_glyph_fragments when processing a GLYPH_INDEX background width that cannot be represented as an INT16. A remote attacker can trick a victim into connecting to a malicious RDP server, negotiate a desktop width of at least 32768 pixels, and send a GLYPH_INDEX order with bkLeft=-32768 and bkRight=32767 to trigger WINPR_ASSERTING_INT_CAST(INT16, bkWidth) and terminate the client.
Affected software
FreeRDP
Remediation
Install security update from vendor's website.
FreeRDP - update to 3.32.2