CVE-2026-40033

high

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

Advisories
More

https://www.vulncheck.com/advisories/freerdp-heap-buffer-overflow-in-gdi-cachetosurface-via-rectangle-validation-bypass

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff

https://github.com/FreeRDP/FreeRDP/commit/23b36cd00ebf0ccd97750fcdbc9aa2f362352da7

Details

Source: Mitre, NVD

Published: 2026-05-26

Updated: 2026-05-27

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 8.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Severity: High

CVSS v4

Base Score: 8.7

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

Severity: High

EPSS

EPSS: 0.00058