Description
The User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Checkbox Field Value in all versions up to, and including, 5.2.8 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The nopriv AJAX action user_registration_user_form_submit reaches ur_process_registration() without nonce validation, meaning any unauthenticated request can reach the vulnerable code path.
References6
- plugins.trac.wordpress.org/browser/user-registration/tags/5.2.8…
- plugins.trac.wordpress.org/browser/user-registration/tags/5.2.8…
- plugins.trac.wordpress.org/browser/user-registration/tags/5.2.8…
- plugins.trac.wordpress.org/browser/user-registration/tags/5.2.8…
- plugins.trac.wordpress.org/changeset/3741339/user-registration/…
- www.wordfence.com/threat-intel/vulnerabilities/id/690d23ee-cf70…
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: 14 · as of 10 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.