The Appointment Hour Booking – Booking Calendar plugin for WordPress is vulnerable to Stored DOM-Based Cross-Site Scripting via Booking Form Single-Line Field via Schedule Calendar List Renderer in all versions up to, and including, 1.5.97 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Exploitation requires the 'list_readmore_numberofwords' Other Parameters setting to be configured with a positive integer value; the default value of 0 bypasses the decode-and-truncate branch entirely and is not exploitable through this sink.