CVE-2026-40033
FreeRDP - Heap-buffer-overflow in gdi_CacheToSurface via rectangle validation bypass
- State
- Published
- Severity
- 8.6 High
- Published
- May 26, 2026
- Updated
- Jul 27, 2026
- Reserved
- Apr 8, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.6 High | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 8.8 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H | VulnCheck |
| 3.1 | 8.8 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H | redhat-SADP |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
FreeRDPFreeRDP |
|
References
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-p6r2-4hgm-m6ffvendor-advisory
- https://github.com/FreeRDP/FreeRDP/pull/12713issue-tracking
- https://github.com/FreeRDP/FreeRDP/commit/d7508ebcd82842a691ae4941e5104d14240a89aepatch
- https://www.vulncheck.com/advisories/freerdp-heap-buffer-overflow-in-gdi-cachetosurface-via-rectangle-validation-bypassthird-party-advisory
- https://access.redhat.com/security/cve/CVE-2026-40033vdb-entry
- RHBZ#2481473issue-tracking
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-40033.json
- https://access.redhat.com/errata/RHSA-2026:46393vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:36203vendor-advisory
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