CVE-2026-40033

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

HIGH
8.8
CVSS Score
Published: May 26, 2026 at 02:08 PM UTC
Updated: July 27, 2026 at 04:27 PM UTC
2 products affected across 2 vendorsFreeRDPEnterprise Linux

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Severity
HIGH8.8
Exploit prediction
EPSS 1%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 3.26.0
Vendor states this is fixed in 3.26.0 (unaffected)
Vendor states this is fixed in 2:3.10.3-12.el10_2.6 (unaffected)
Vendor states this is fixed in 7 (unaffected)
Vendor states this is fixed in 8 (unaffected)
Vendor states this is fixed in 6 (unknown)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.8HIGHVulnCheck
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-122CWE-787

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