CVE-2026-1708: Croixhaug Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to blind SQL Injection in all versions up to, and including, 1.6.9.27. This is due to the `db_where_conditions` method in the `TD_DB_Model` class failing to prevent the `append_where_sql` parameter from being passed through JSON request bodies, while only checking for its presence in the `$_REQUEST` superglobal. This makes it possible for unauthenticated attackers to append arbitrary SQL commands to queries and extract sensitive information from the database via the `append_where_sql` parameter in JSON payloads granted they have obtained a valid `public_token` that is inadvertently exposed during the booking flow.

Affected products

• Croixhaug Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin: up to and including 1.6.9.27

Published 2026-03-11. Last modified 2026-06-17.