CVE-2026-36540

High severity, CVSS 7.3. EPSS: 1.3% chance of exploitation in the next 30 days.

Netis AC1200 Router NC21 V4.0.1.4296 is vulnerable to unauthenticated command injection via the /cgi-bin/skk_set.cgi endpoint. The password and new_pwd_confirm POST parameters are passed directly to the underlying OS shell without sanitization. An attacker can inject arbitrary shell commands by wrapping them in backticks (`) and encoding them in base64. Because the endpoint requires no authentication, any device on the LAN can achieve full Remote Code Execution on the router's operating system with a single HTTP POST request.

Published 2026-05-27. Last modified 2026-07-05.