Login No Captcha reCAPTCHA <= 1.8.0 - Unauthenticated Stored Cross-Site Scripting via PHP_SELF
Strategic Overview
- Status
- Patched in 1.8.1
- Affected Plugin
- Login No Captcha reCAPTCHA
- Affected Version
<= 1.8.0- CVSS
- 7.2High
- Weakness type
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- CVE
CVE-2026-2374
At a glance
CVE-2026-2374 is a high-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Login No Captcha reCAPTCHA WordPress plugin, affecting versions <= 1.8.0. It carries a CVSS score of 7.2 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 1.8.1; sites on affected versions should update now. Disclosed May 2026, reported by ISMAILSHADOW.
Vulnerability Overview
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.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user.
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Login No Captcha reCAPTCHA <= 1.8.0 carries this weakness at PHP_SELF, and reaching it takes no account at all. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.
Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Login No Captcha reCAPTCHA the fix is 1.8.1: builds <= 1.8.0 are affected, anything from 1.8.1 onward is not.
Remediation
Update to version 1.8.1, or a newer patched version
How does WordSec protect against this?
Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Login No Captcha reCAPTCHA 1.8.1 closes this, and updating the plugin is the step that ends it.
- Firewall
- Login Security
- Alerts
External References
Related records
Other vulnerabilities in Login No Captcha reCAPTCHA
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