CVE-2026-13039

/// Technical description

The Eventin – Event Calendar, Event Registration, Tickets & Booking (AI Powered) plugin for WordPress is vulnerable to authorization bypass due to a regression in versions from 4.0.26 up to and including 4.1.15. This is due to the plugin not properly verifying that a user is authorized to perform an action in the payment_complete() function of PaymentController.php. This makes it possible for unauthenticated attackers to mark unpaid ticket orders as completed by submitting a fabricated SureCart checkout ID or FluentCart cart hash, granting themselves paid event access, QR-code attendee tickets, and order confirmation emails without making any real payment. The wp_rest nonce required to reach the vulnerable endpoint is embedded in every public event page, meaning no WordPress session or credentials are needed to obtain it. This vulnerability represents a regression — the same function and endpoint were previously patched but the fix did not persist through subsequent releases.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References