Description

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to denial of service in all versions up to, and including, 1.6.11.5. This is due to a publicly accessible REST API endpoint (/wp-json/ssa/v1/async) that calls PHP's sleep() function on a user-supplied delay parameter without any rate limiting. This makes it possible for unauthenticated attackers to exhaust PHP worker processes, denying access to the site to legitimate users.

Dates

Published: 2026-05-27 · Last Modified: 2026-05-27

Weaknesses

References

• https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.11.2/includes/class-async-action-model.php#L173
• https://www.wordfence.com/threat-intel/vulnerabilities/id/ae66228e-d086-44fd-8acb-5a99482cedfb?source=cve