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.
History

Tue, 20 Jan 2026 08:45:00 +0000

Type Values Removed Values Added
First Time appeared Freerdp
Freerdp freerdp
Vendors & Products Freerdp
Freerdp freerdp

Tue, 20 Jan 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H'}

threat_severity

Important


Mon, 19 Jan 2026 17:15:00 +0000

Type Values Removed Values Added
Description 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.
Title FreeRDP has heap-buffer-overflow in clear_decompress
Weaknesses CWE-122
References
Metrics cvssV4_0

{'score': 7.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-01-19T17:01:01.380Z

Updated: 2026-01-19T17:01:01.380Z

Reserved: 2026-01-13T18:22:43.981Z

Link: CVE-2026-23531

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-01-19T17:15:50.897

Modified: 2026-01-19T17:15:50.897

Link: CVE-2026-23531

cve-icon Redhat

Severity : Important

Publid Date: 2026-01-19T17:01:01Z

Links: CVE-2026-23531 - Bugzilla