CVE-2026-40033 PUBLISHED

FreeRDP - Heap-buffer-overflow in gdi_CacheToSurface via rectangle validation bypass

Assigner: VulnCheck
Reserved: 08.04.2026 Published: 26.05.2026 Updated: 26.05.2026

FreeRDP before 3.26.0 contains a heap-buffer-overflow vulnerability in gdi_CacheToSurface that allows remote attackers to write out-of-bounds heap memory. The vulnerability occurs because rectangle validation clamps coordinates to UINT16_MAX but performs copy operations using unclamped cache entry dimensions, enabling malicious RDP servers to trigger large out-of-bounds writes and potentially achieve remote code execution or client crash.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.6

Product Status

Vendor FreeRDP
Product FreeRDP
Versions Default: unaffected
  • affected from 0 to 3.26.0 (excl.)
  • Version 3.26.0 is unaffected

Credits

  • kevin-valerio reporter

References

Problem Types

  • Heap-based Buffer Overflow CWE