CVE-2026-92798User Registration & Membership <= 5.2.8 - Authenticated (Subscriber+) Arbitrary Shortcode Execution via Referer Header via 'referrer_url' Smart Tag

Descripción

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.

Datos: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Se publican tal como los indican las fuentes, en inglés.

Productos y versiones afectados

Referencias y parches

• 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-urc…
• https://plugins.trac.wordpress.org/browser/user-registration/tags/5.2.8/modules/content-restriction/functions…
• https://plugins.trac.wordpress.org/changeset/3741339/user-registration/trunk/includes/class-ur-smart-tags.php