PatchTheCVECVE-2026-40033: FreeRDP before 3.26.0 contains a heap-buffer-overflow vulnerability in gdi_CacheToSurface that allows remote a
CVE-2026-40033 is a high-severity flaw (CVSS 8.8) affecting freerdp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- High severity
- Public exploit reference
A fixed release or distro patch exists.
Last updated 2026-07-27 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-40033?
freerdp: upgrade to 3.26.0. Exact commands for each OS are on this page.
Is CVE-2026-40033 being exploited?
CVE-2026-40033 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-40033 affect?
CVE-2026-40033 affects freerdp. Severity is high (CVSS 8.8). 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_MA
How urgent is CVE-2026-40033?
Priority 54/100. High severity; Public exploit reference
Software pages
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