CVE-2026-23531
January 19, 2026
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, in ClearCodec, when "glyphData" is present, "clear_decompress" calls "freerdp_image_copy_no_overlap" without validating the destination rectangle, allowing an out-of-bounds read/write via crafted RDPGFX surface updates. 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 Packages
https://github.com/FreeRDP/FreeRDP.git (GITHUB):
Affected version(s) >=1.0-beta1 <3.21.0Fix Suggestion:
Update to version 3.21.0Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
7.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
Exploit Maturity
POC
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Heap-based Buffer Overflow
EPSS
Base Score:
0.09
