Description
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.
References7
- plugins.trac.wordpress.org/browser/login-recaptcha/tags/1.7.3/l…
- plugins.trac.wordpress.org/browser/login-recaptcha/tags/1.7.3/l…
- plugins.trac.wordpress.org/browser/login-recaptcha/trunk/login-…
- plugins.trac.wordpress.org/browser/login-recaptcha/trunk/login-…
- plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&repo…
- wordpress.org/plugins/login-recaptcha/
- www.wordfence.com/threat-intel/vulnerabilities/id/99dfce3b-2b47…
Metrics
- CVSS 3.1
-
7.2
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 29 · as of 15 November 2026
- CWE
- CWE-79
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.