What’s Vulnerable › Vulnerabilities
CVE-2026-23532: FreeRDP has heap-buffer-overflow in gdi_SurfaceToSurface
- Severity: critical (CVSS 9.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.5% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2026-01-19 · updated 2026-07-15
- Weakness: CWE-122
Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, a client-side heap buffer overflow occurs in the FreeRDP client’s `gdi_SurfaceToSurface` path due to a mismatch between destination rectangle clamping and the actual copy size. A malicious server can trigger a client‑side heap buffer overflow, causing a crash (DoS) and potential heap corruption with code‑execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.
Affected products
- FreeRDP: before 3.21.0 — fixed in 3.21.0
How to fix
Upgrade to a fixed version: FreeRDP 3.21.0. Check the vendor advisory for mitigations.
References
- https://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/gdi/gfx.c#L1368-L1382
- https://github.com/FreeRDP/FreeRDP/releases/tag/3.21.0
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-fq8c-87hj-7gvr
- https://access.redhat.com/errata/RHSA-2026:2048
- https://access.redhat.com/errata/RHSA-2026:2081
- https://access.redhat.com/errata/RHSA-2026:2222
- https://access.redhat.com/errata/RHSA-2026:2714
- https://access.redhat.com/errata/RHSA-2026:2736
- https://access.redhat.com/errata/RHSA-2026:2770
- https://access.redhat.com/errata/RHSA-2026:2824
- https://access.redhat.com/errata/RHSA-2026:2952
- https://access.redhat.com/errata/RHSA-2026:3036
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