CVE-2026-44421 — FreeRDP RDPGFX CacheToSurface heap-buffer-overflow via clamped-rectangle validation bypass
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 sendin…
Published: 2026-05-29 · CVSS: 8.8 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7