Vulnerability · Published Oct 17, 2026 · Assigned by Wordfence
CVE-2026-92798User Registration & Membership <= 5.2.8 - Authenticated (Subscriber+) Arbitrary Shortcode Execution via Referer Header via 'referrer_url' Smart Tag
High 8.1
In plain English
A high-severity code injection in User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder from wpeverest. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities).
Official description
The User Registration & Membership plugin for WordPress is vulnerable to Arbitrary Shortcode Execution in versions up to, and including, 5.2.8 This is due to insufficient input sanitization in the 'referrer_url' branch of UR_Smart_Tags::process(), where the attacker-controlled HTTP_REFERER header is only passed through sanitize_text_field() — which does not strip WordPress shortcode delimiters — before being substituted into a Content Restriction message that is subsequently executed via apply_shortcodes()/do_shortcode(). This makes it possible for unauthenticated attackers to execute arbitrary registered shortcodes on any restricted page whose message uses the supported {{referrer_url}} smart tag.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| wpeverest | User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder | 0 – through 5.2.8 |
Weakness: CWE-94 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
References
- https://www.wordfence.com/threat-intel/vulnerabilities/id/ec317df9-c7ef-49a3-9818-903dfe4bdd03?source=cve
- https://plugins.trac.wordpress.org/browser/user-registration/tags/5.2.8/includes/class-ur-smart-tags.php#L475
- https://plugins.trac.wordpress.org/browser/user-registration/tags/5.2.8/includes/class-ur-smart-tags.php#L474
- https://plugins.trac.wordpress.org/browser/user-registration/tags/5.2.8/modules/content-restriction/class-urcr-frontend.php#L1383
- https://plugins.trac.wordpress.org/browser/user-registration/tags/5.2.8/modules/content-restriction/functions-urcr-core.php#L693
- https://plugins.trac.wordpress.org/changeset/3741339/user-registration/trunk/includes/class-ur-smart-tags.php