CVE-2026-40033
FreeRDP - Heap-buffer-overflow in gdi_CacheToSurface via rectangle validation bypass
CVSS Score
8.8
EPSS Score
0.8%
EPSS Percentile
53th
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.
| CWE | CWE-122 |
| Vendor | freerdp |
| Product | freerdp |
| Published | May 26, 2026 |
| Last Updated | Jul 16, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
FreeRDP / FreeRDP
0 < 3.26.0
References
github.com: https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff github.com: https://github.com/FreeRDP/FreeRDP/pull/12713 github.com: https://github.com/FreeRDP/FreeRDP/commit/d7508ebcd82842a691ae4941e5104d14240a89ae vulncheck.com: https://www.vulncheck.com/advisories/freerdp-heap-buffer-overflow-in-gdi-cachetosurface-via-rectangle-validation-bypass access.redhat.com: https://access.redhat.com/security/cve/CVE-2026-40033 bugzilla.redhat.com: https://bugzilla.redhat.com/show_bug.cgi?id=2481473 security.access.redhat.com: https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40033.json access.redhat.com: https://access.redhat.com/errata/RHSA-2026:36203
Credits
🔍 kevin-valerio