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
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.
INFO
Published Date :
Sept. 16, 2026, 5:16 a.m.
Last Modified :
Sept. 16, 2026, 5:16 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-89063
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update the Bookly plugin to the latest version.
- Verify that the 'conversation_id' parameter is validated.
- Ensure conversations have owner and session identifiers.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-89063.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-89063 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-89063
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-89063 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-89063 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Sep. 16, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-639 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/89xxx/CVE-2026-89063.json">CVE-2026-89063</a> Added Reference https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/28.1/frontend/modules/ai/Ajax.php#L212 Added Reference https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/28.1/frontend/modules/ai/Ajax.php#L215 Added Reference https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/28.1/frontend/modules/ai/Ajax.php#L38 Added Reference https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/28.1/frontend/modules/ai/Ajax.php#L60 Added Reference https://plugins.trac.wordpress.org/browser/bookly-responsive-appointment-booking-tool/tags/28.1/lib/base/Component.php#L67 Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/b6af015f-f954-4afb-9d65-56176f73672f?source=cve