CVE-2026-86841: Unknown Online Scheduling And Appointment Booking System

Medium severity, CVSS 4.7. 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 prevent deserialization of untrusted input and does not correctly restrict a privileged maintenance feature to administrators, allowing users granted a custom booking-management capability, which an administrator must explicitly assign, to inject arbitrary PHP objects, overwrite privileged site options, and read stored integration secrets.

Affected products

• Unknown Online Scheduling And Appointment Booking System: from 23.2, before 28.3 (fixed in 28.3)

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