Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin, CVE-2026-89294

CVE, Research URL: CVE-2026-89294
Home page URL: Security reports for Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin
Application: Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin
Published on: Sep 30, 2026
Research Description: The Simply Schedule Appointments plugin for WordPress is vulnerable to Local File Inclusion in all versions up to, and including, 1.6.12.27 via the 'ssa_locale' parameter parameter. This makes it possible for authenticated attackers, with subscriber-level access and above, to include and execute arbitrary .php files on the server, allowing the execution of any PHP code in those files. This can be used to bypass access controls, obtain sensitive data, or achieve code execution in cases where .php file types can be uploaded and included. Notably, exploitation does not require authentication in practice, as the locale filter is installed unconditionally on every request during plugins_loaded and the callback performs no nonce or capability check before returning the raw GET parameter value.
Affected versions: max 1.6.12.33.
Status: vulnerable