Medium [CVE-2026-67300] Use-After-Free vulnerability leading to denial of service

FreeRDP before 3.29.0 contains client-side heap use-after-free vulnerabilities in the async update message proxy for RAIL WINDOW_STATE_ORDER and NOTIFY_ICON_STATE_ORDER when AsyncUpdate is enabled.

When a malicious or compromised RDP server sends crafted update orders, the message proxy shallow-copies structures containing nested parser-owned pointers (e.g., titleInfo.string, windowRects, visibilityRects, icon buffers).

The parser frees those nested buffers after the callback returns, so the queued async message later dispatches stale pointers, potentially causing memory corruption or a client crash. A flaw was found in FreeRDP.

This client-side heap use-after-free vulnerability occurs when a malicious or compromised Remote Desktop Protocol (RDP) server sends specially crafted update orders. The async update message proxy incorrectly handles memory by shallow-copying structures with pointers that are later freed by the parser.

This leads to the use of stale pointers, which can cause memory corruption or a client crash, resulting in a denial of service. Red Hat severity: Moderate — CVSS 6.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H).

Weakness: CWE-825. Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 7; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9.