CVE-2026-23530
Severity CVSS v4.0:
HIGH
Type:
CWE-122
Heap-based Buffer Overflow
Publication date:
19/01/2026
Last modified:
19/01/2026
Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0,`freerdp_bitmap_decompress_planar` does not validate `nSrcWidth`/`nSrcHeight` against `planar->maxWidth`/`maxHeight` before RLE decode. 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.
References to Advisories, Solutions, and Tools
- https://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/codec/planar.c#L1689-L1696
- https://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/codec/planar.c#L1713-L1716
- https://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/codec/planar.c#L951-L953
- https://github.com/FreeRDP/FreeRDP/releases/tag/3.21.0
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-r4hv-852m-fq7p



