CVE-2026-40033

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

Published May 26, 2026 CVSS 4.0 · 8.6 High EPSS 1.4% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-8561-1 FreeRDP vulnerabilities
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title FreeRDP - Heap-buffer-overflow in gdi_CacheToSurface via rectangle validation bypass
First Time appeared Freerdp
Freerdp freerdp
Weaknesses CWE-122
CPEs cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*
Vendors & Products Freerdp
Freerdp freerdp
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 8.6, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Nov 8, 2026, 2:02 PM
Reserved
Apr 8, 2026, 1:36 PM
Status
Modified
Published
May 26, 2026, 3:16 PM
Modified
Jul 27, 2026, 1:17 PM