CVE-2026-23534

19.01.2026, 18:16

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 ClearCodec bands decode path when crafted band coordinates allow writes past the end of the destination surface buffer. A malicious server can trigger a clientside heap buffer overflow, causing a crash (DoS) and potential heap corruption with codeexecution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	NIST	UNKNOWN				---
GitHub_M	CNA	---				---

Base Score

CVSS 3.x

EPSS Score

Percentile: Unknown

Debian Releases

Debian Product

Codename

freerdp2

bullseye	vulnerable
bullseye (security)	vulnerable
bookworm	vulnerable

freerdp3

trixie	vulnerable
forky	vulnerable
sid	vulnerable

Common Weakness Enumeration

CWE-122 - Heap-based Buffer Overflow
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

References

https://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/codec/clear.c#L878-L879

https://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/codec/clear.c#L883-L884

https://github.com/FreeRDP/FreeRDP/releases/tag/3.21.0

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-3frr-mp8w-4599