CVE-2026-40033: FreeRDP - Heap-buffer-overflow in gdi_CacheToSurface via rectangle validation bypass
FreeRDP before 3.26.0 contains a heap-buffer-overflow vulnerability in gdiCacheToSurface that allows remote attackers to write out-of-bounds heap memory. The vulnerability occurs because rectangle validation clamps coordinates to UINT16MAX 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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
FreeRDPto a version that resolves this vulnerability.Fixed in 3.26.0
Event History
Frequently Asked Questions
What is the severity of CVE-2026-40033?
The severity of CVE-2026-40033 is rated high with a score of 8.8.
How do I fix CVE-2026-40033?
To fix CVE-2026-40033, update to FreeRDP version 3.26.0 or later where the vulnerability has been addressed.
What type of vulnerability is CVE-2026-40033?
CVE-2026-40033 is a heap-buffer-overflow vulnerability.
Who is affected by CVE-2026-40033?
Users of FreeRDP versions prior to 3.26.0 are affected by CVE-2026-40033.
What can attackers achieve with CVE-2026-40033?
Attackers can exploit CVE-2026-40033 to write out-of-bounds heap memory, potentially leading to arbitrary code execution.