CVE-2026-86839: Unknown Online Scheduling And Appointment Booking System

Low severity, CVSS 3.8. EPSS: 0.2% chance of exploitation in the next 30 days.

The Online Scheduling and Appointment Booking System WordPress plugin before 28.3 does not verify that appointment and payment records requested through its staff-role AJAX actions belong to the requesting staff member, allowing authenticated attackers with a staff-level account to view, modify and delete other staff members' appointments and payments, including the associated customer's personal information.

Affected products

• Unknown Online Scheduling And Appointment Booking System: before 28.3 (fixed in 28.3)

Published 2026-09-27. Last modified 2026-09-28.