Published: May 28, 2026 | Last Modified: May 28, 2026
The Login No Captcha reCAPTCHA plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `$_SERVER['PHP_SELF']` superglobal in all versions up to, and including, 1.8.0. This is due to the `authenticate()` function storing the unsanitized output of `basename($_SERVER['PHP_SELF'])` in the `login_nocaptcha_error` WordPress option when a login attempt is made from a non-standard login page (e.g., xmlrpc.php). The `admin_notices()` function then echoes this stored value directly into the admin dashboard HTML without escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute when an administrator with a whitelisted IP address visits the WordPress dashboard within 30 seconds of the attack.
This analysis is generated by Ghostwire from NVD, CISA KEV, EPSS, and open-source intelligence data. Verify findings through primary sources before acting.