CVE-2026-40033

HIGH

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

Title source: cna
STIX 2.1

Description

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.

References (3)

Core 3
Core References
Vendor Advisory vendor-advisory
GHSA Advisory GHSA-p6r2-4hgm-m6ff
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff
Third Party Advisory third-party-advisory
VulnCheck Advisory: FreeRDP - Heap-buffer-overflow in gdi_CacheToSurface via rectangle validation bypass
https://www.vulncheck.com/advisories/freerdp-heap-buffer-overflow-in-gdi-cachetosurface-via-rectangle-validation-bypass

Scores

CVSS v3 8.8
EPSS 0.0066
EPSS Percentile 46.6%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact total

Details

CWE
CWE-122
Status published
Products (3)
FreeRDP/FreeRDP < 3.26.0
freerdp/freerdp < 3.26.0
FreeRDP/FreeRDP 3.26.0
Published May 26, 2026
Tracked Since May 26, 2026