CVE-2026-6203

Description

The User Registration & Membership plugin for WordPress is vulnerable to Open Redirect in versions up to and including 5.1.4. This is due to insufficient validation of user-supplied URLs passed via the 'redirect_to_on_logout' GET parameter before redirecting users. The `redirect_to_on_logout` GET parameter is passed directly to WordPress's `wp_redirect()` function instead of the domain-restricted `wp_safe_redirect()`. While `esc_url_raw()` is applied to sanitize malformed URLs, it does not restrict the redirect destination to the local domain, allowing an attacker to craft a specially formed link that redirects users to potentially malicious external URLs after logout, which could be used to facilitate phishing attacks.

CVSS breakdown

Affected products

• wpeverest / User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder0 – 5.1.4

Exploits & PoCs

• nucleiUser Registration & Membership WordPress plugin - Open Redirectby theamanrawat

References

• MISChttps://www.wordfence.com/threat-intel/vulnerabilities/id/020bed37-9544-49b7-941d-3b7f509fdfdf?source=cve
• MISChttps://plugins.trac.wordpress.org/browser/user-registration/trunk/includes/functions-ur-template.php#L39
• MISChttps://plugins.trac.wordpress.org/browser/user-registration/tags/5.1.4/includes/functions-ur-template.php#L39