Use After Free in Freerdp
CVE-2026-67299
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.
Vulnerability class: Use-After-Free
EPSS: 0.003 (27.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Freerdp — versions 0, 3.29.0
Weakness classification (CWE)
References
- disclosure@vulncheck.com (Exploit, vendor-advisory, Vendor Advisory)
- disclosure@vulncheck.com (Patch, patch)
- disclosure@vulncheck.com (Patch, Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-67299?
- CVE-2026-67299 is a high-severity vulnerability in Freerdp, classified under Use After Free. CVSS score: 7.5/10. Published 2026-08-01.
- How severe is CVE-2026-67299?
- High severity. CVSS v3 base score is 7.5 out of 10.