CVE-2026-27929: Local Privilege Escalation in LUAFV

The primary impact of CVE-2026-27929 is local privilege escalation. An attacker who has already gained a foothold on the system (e.g., through a phishing attack or compromised account) can exploit this TOCTOU race condition to gain higher privileges, such as SYSTEM access. This allows the attacker to execute arbitrary code with elevated privileges, install malware, modify system settings, and potentially compromise the entire system. The ability to escalate privileges locally is a common attack vector for gaining persistent access and control over a system.

1. Veröffentlicht2026-04-14
2. Geändert2026-05-12
3. EPSS aktualisiert2026-04-22

The primary mitigation for CVE-2026-27929 is to upgrade affected Windows systems to version 10.0.28000.1836 or later. Microsoft has released a security update specifically addressing this vulnerability. If immediate patching is not feasible, consider implementing least privilege principles to limit the potential impact of a successful privilege escalation. While a WAF or proxy cannot directly prevent this vulnerability, they can help detect and block suspicious network traffic. After upgrading, confirm the fix by attempting to reproduce the TOCTOU race condition and verifying that privilege escalation is prevented.