CVE-2026-12378 [HIGH] – The Appointment Booking Calendar Plugin and Scheduling Plugin WordPress plugin through 1.

The Appointment Booking Calendar Plugin and Scheduling Plugin WordPress plugin through 1.1.28 does not validate data before passing it to a PHP deserialization function, allowing unauthenticated attackers to inject arbitrary PHP objects; where a suitable gadget chain is present on the site this can be leveraged to achieve remote code execution.