Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-08-01T12:22:18 FreeRDP: FreeRDP: Denial of Service via crafted WindowIcon async message 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H CWE-416

FreeRDP before 3.29.0 contains a client-side heap use-after-free in the async update message proxy for WINDOW_ICON_ORDER when AsyncUpdate is enabled (e.g. xfreerdp /async-update). In update_message_WindowIcon() a shallow CopyMemory() overwrites a freshly allocated lParam->iconInfo with the parser-owned windowIcon->iconInfo pointer. After the parser callback returns, update_recv_window_info_order() frees window_icon.iconInfo, but the queued async message still retains and later dispatches that stale pointer. A malicious or compromised RDP server sending a crafted RAIL Window Alternate Secondary Order with WINDOW_ORDER_ICON can trigger use-after-free, leading to memory corruption and client crash.

A flaw was found in FreeRDP. A malicious or compromised Remote Desktop Protocol (RDP) server can exploit a heap use-after-free vulnerability when a client connects with asynchronous updates enabled. By sending a specially crafted Window Alternate Secondary Order message, the server can trigger memory corruption, leading to a client crash and a denial of service.

This is a Moderate client-side flaw in FreeRDP. When a user connects to a malicious RDP server with asynchronous updates explicitly enabled, a heap use-after-free vulnerability can be triggered. This leads to memory corruption and a denial of service on the client system, but requires user interaction with a compromised server. To mitigate this issue, avoid connecting to untrusted RDP servers. Additionally, refrain from using the `/async-update` command-line option when launching FreeRDP clients, as this feature is required to trigger the vulnerability. Red Hat Enterprise Linux 10 Affected freerdp Red Hat Enterprise Linux 6 Out of support scope freerdp Red Hat Enterprise Linux 7 Affected freerdp Red Hat Enterprise Linux 8 Affected freerdp Red Hat Enterprise Linux 9 Affected freerdp https://www.cve.org/CVERecord?id=CVE-2026-67299 https://nvd.nist.gov/vuln/detail/CVE-2026-67299 https://github.com/FreeRDP/FreeRDP/commit/5370fb26fbf034ecd11d3026b6ad639b5fff493f https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-34hq-hwjw-q8v3 https://www.vulncheck.com/advisories/freerdp-before-use-after-free-via-windowicon-async-message