---
id: CVE-2026-89063
title: >-
  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…
summary: >-
  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…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-639
vendor: ladela
product: Online Scheduling and Appointment Booking System – Bookly
affected:
  - online_scheduling_and_appointment_booking_system_bookly <= 28.1
published: '2026-09-16'
updated: '2026-09-17'
sourceUpdated: '2026-09-17T18:17:14.140'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89063'
references:
  - url: >-
      https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/28.1/frontend/modules/ai/Ajax.php#L212
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/28.1/frontend/modules/ai/Ajax.php#L215
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/28.1/frontend/modules/ai/Ajax.php#L38
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/28.1/frontend/modules/ai/Ajax.php#L60
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/28.1/lib/base/Component.php#L67
    label: security@wordfence.com
  - url: >-
      https://www.wordfence.com/threat-intel/vulnerabilities/id/b6af015f-f954-4afb-9d65-56176f73672f?source=cve
    label: security@wordfence.com
tags:
  - nvd
  - cve.org
  - exploit-available
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-17T17:39:04.337616Z'
epss: 0.00392
epssPercentile: 0.33168
ingestedAt: '2026-09-16T04:49:46.353Z'
exploits:
  nuclei:
    - CVE-2026-89063
  checkedAt: '2026-09-24T07:53:23.312Z'
exploitAvailable: true
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.