CVE-2026-23531

CVE Details

Release Date:	2026-01-19
Impact:	Important	What is this?

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.

See more information about CVE-2026-23531 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	7.6
Vector String:	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
Version:	3.1
Attack Vector:	Network
Attack Complexity:	Low
Privileges Required:	None
User Interaction:	Required
Scope:	Unchanged
Confidentiality Impact:	Low
Integrity Impact:	Low
Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 8 (freerdp)	ELSA-2026-2081	2026-02-05
Oracle Linux version 9 (freerdp)	ELSA-2026-2048	2026-02-05