CVE-2026-40033
HIGHFreeRDP - Heap-buffer-overflow in gdi_CacheToSurface via rectangle validation bypass
Title source: cnaDescription
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 (10)
Core 10
Core References
Issue Tracking issue-tracking
https://github.com/FreeRDP/FreeRDP/pull/12713
Vendor Advisory
https://access.redhat.com/security/cve/CVE-2026-40033
Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2481473
Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:36203
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
Vendor Advisory vendor-advisory
GHSA Advisory GHSA-p6r2-4hgm-m6ff
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff
Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:46393
Scores
CVSS v3
8.8
EPSS
0.0104
EPSS Percentile
60.5%
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
CWE-787
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