CVE-2026-44421: Freerdp

High severity, CVSS 8.8. EPSS: 0.7% chance of exploitation in the next 30 days.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, a malicious RDP server can trigger a heap-buffer-overflow write in the FreeRDP client by sending crafted RDPGFX PDUs. The bug is in gdi_CacheToSurface: it validates a destination rectangle that is clamped to UINT16_MAX, but then performs the copy using the original cacheEntry->width/height. This can cause a large out-of-bounds heap write and may lead to client crashes or code execution. This bug is reachable from a malicious RDP server, but only when the client has RDPGFX enabled. This vulnerability is fixed in 3.26.0.

Affected products

• Freerdp Freerdp: before 3.26.0 (fixed in 3.26.0)

Published 2026-05-29. Last modified 2026-07-27.