CVE-2026-40033
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.
- Score
- CVSS 3.1 8.8 High
- Status
- Modified - disclosure@vulncheck.com
- Published
- 2026-05-26
- Last modified
- 2026-07-27
- Weaknesses
- CWE-122, CWE-787
Affected products
References
- https://github.com/FreeRDP/FreeRDP/commit/d7508ebcd82842a691ae4941e5104d14240a89ae
- https://github.com/FreeRDP/FreeRDP/pull/12713
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ff
- https://www.vulncheck.com/advisories/freerdp-heap-buffer-overflow-in-gdi-cachetosurface-via-rectangle-validation-bypass
- https://access.redhat.com/errata/RHSA-2026:36203
- https://access.redhat.com/errata/RHSA-2026:46393
- https://access.redhat.com/security/cve/CVE-2026-40033
- https://bugzilla.redhat.com/show_bug.cgi?id=2481473
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40033.json
