CVE-2026-89063

High

Description

The Online Scheduling and Appointment Booking System – Bookly plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 28.1 via the 'conversation_id' parameter due to missing validation on a user controlled key. This makes it possible for unauthenticated attackers to read the full AI booking conversation transcript of any customer — leaking names, email addresses, phone numbers, and appointment details echoed by the assistant — and inject arbitrary messages into any victim conversation that are subsequently replayed to the Cloud AI worker along with the full private history. Because AI conversations are stored with no owner, user, or session identifier and conversation IDs are sequential integers, an unauthenticated attacker can enumerate all customer conversations simply by incrementing the conversation_id parameter.

SeverityHigh
CVSS7.5
Exploit probability—
ProductOnline Scheduling and Appointment Booking System – Bookly
PublishedSep 16, 2026
First seenSep 16, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
ladela Online Scheduling and Appointment Booking System – Booklyv ≤ 28.1—

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