CVE-2026-23531

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.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/FreeRDP/FreeRDP/blob/38514dfa5813aa945a86cfbcec279033f8394468/libfreerdp/codec/clear.c#L1139-L1145	Product
https://github.com/FreeRDP/FreeRDP/releases/tag/3.21.0	Release Notes
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-xj5h-9cr5-23c5	Exploit Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:freerdp:freerdp:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-01-19 17:15

Updated : 2026-01-28 18:51

NVD link : CVE-2026-23531

Mitre link : CVE-2026-23531

CVE.ORG link : CVE-2026-23531

JSON object : View

Products Affected

freerdp

freerdp

CWE

CWE-122

Heap-based Buffer Overflow

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