CVE-2026-1708

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.

• https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.9.21/includes/class-appointment-model.php#L1340
• https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.9.21/includes/class-appointment-model.php#L1413
• https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.9.21/includes/lib/td-util/class-td-db-model.php#L1019
• https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.9.21/includes/lib/td-util/class-td-db-model.php#L1025
• https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/trunk/includes/class-appointment-model.php#L1340
• https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/trunk/includes/class-appointment-model.php#L1413
• https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/trunk/includes/lib/td-util/class-td-db-model.php#L1019
• https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/trunk/includes/lib/td-util/class-td-db-model.php#L1025
• https://plugins.trac.wordpress.org/changeset/3475885/simply-schedule-appointments/trunk/includes/lib/td-util/class-td-db-model.php
• https://www.wordfence.com/threat-intel/vulnerabilities/id/71642341-9fe0-44a9-88f3-70167dc6ca62?source=cve