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CVE-2026-40033

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

Published: May 26, 2026Updated: May 26, 2026 Sources: CVE List NVD
NVD MITRE
8.8CVSS
HIGH

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.

EPSS Score
N/A
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available

CVSS Vector Breakdown

AV:NAC:LPR:NUI:RS:UC:HI:HA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:RUser Interaction
Required
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High

Weaknesses

CWE-122

Affected Products

FreeRDP
FreeRDP

Attack Graph

Products CVE Techniques Tactics

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Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

MITRE ATT&CK

1 technique
Privilege Escalation
View detailed technique mapping

References

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff
github.com
https://github.com/FreeRDP/FreeRDP/commit/23b36cd00ebf0ccd97750fcdbc9aa2f362352da7
github.com
https://www.vulncheck.com/advisories/freerdp-heap-buffer-overflow-in-gdi-cachetosurface-via-rectangle-validation-bypass
vulncheck.com

Timeline

Published
May 26, 2026
Last Updated
May 26, 2026

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