Online Scheduling and Appointment Booking System <= 28.2 — Insecure Direct Object Reference to Unauthenticated Arbitrary Booking Token Disclosure and Deletion via 'order_id' Parameter
CVE-2026-93399Published · Updated Action summary
Affected: ≤28.2Update to 28.3 or newer
All remediation steps- Severity
- Critical9.1
- CVSS
- 9.1CVSS 3.1 · CNA (Wordfence)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:HWhat does this vector mean?
AV:NAttack vector- Network
AC:LAttack complexity- Low
PR:NPrivileges required- None
UI:NUser interaction- None
S:UScope- Unchanged
C:NConfidentiality- None
I:HIntegrity- High
A:HAvailability- High
- Required access
- No account needed
- Exploit prediction (EPSS)
- 0.6% chance in 30 days48th percentile
- CISA KEV
- Not listed
On this page8
Am I affected?
Online Scheduling and Appointment Booking System – Bookly bookly-responsive-appointment-booking-tool
- Affected≤ 28.2
- Patched in28.3
Update to 28.3 or newer.
You are affected if you run ≤ 28.2. Version 28.3 and later are not affected by this issue.
- Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Online Scheduling and Appointment Booking System – Bookly.
- No admin access? Run a passive check of your site. It reads public files only.
- No account is needed to exploit this. Treat any exposed site on an affected version as at risk.
What to do
- Update to version 28.3, or a newer patched version
- Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
- Watch Online Scheduling and Appointment Booking System – Bookly to get an email when the next vulnerability is published.
Advisory
Source description from Wordfence Intelligence, credited to Theklis.
The Bookly plugin for WordPress is vulnerable to Insecure Direct Object Reference in versions up to, and including, 28.2 via the 'bookly_get_form_id', 'bookly_render_complete', 'bookly_add_to_calendar' and 'bookly_rollback_order' AJAX actions. This is due to the 'bookly_get_form_id' handler blindly storing the attacker-controlled 'order_id' from the submitted form_data into a new booking session, which the 'bookly_render_complete' handler then trusts to look up and return the corresponding Order's secret token without verifying that the current session created that order. This makes it possible for unauthenticated attackers to enumerate sequential order IDs, disclose other customers' order tokens, retrieve calendar/appointment information via 'bookly_add_to_calendar' and permanently delete arbitrary non-completed bookings via 'bookly_rollback_order', which cascade-deletes the customer_appointment and (when no other customers are attached) the underlying appointment.
Exploits & references
Proof-of-concept & detection
No public proof-of-concept or detection template is known for this vulnerability.
Advisories & patches
- Advisorywordfence.com
Related CVEs
More in Online Scheduling and Appointment Booking System – Bookly
All 32| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| High7.2 | Authenticated (Custom+) PHP Object Injection via 'value' Parameter ≤28.2Update to 28.3 | CVE-2026-12626 | |
| Medium6.8 | Insecure Direct Object Reference to Authenticated (Subscriber+) Privilege Escalation via 'id' and 'wp_user_id' Parameters via Query String / JSON Body ≤28.4Update to 28.5 | CVE-2026-104898 | |
| Medium5.3 | Unauthenticated Sensitive Information Exposure in 'phone' Parameter to bookly_render_details ≤28.4Update to 28.5 | CVE-2026-103365 | |
| Medium4.3 | Authenticated (Staff+) Insecure Direct Object Reference ≤28.2Update to 28.3 | CVE-2026-86839 | |
| Medium5.3 | Unauthenticated Payment Bypass ≤28.2Update to 28.3 | CVE-2026-86838 |
- High7.2Authenticated (Custom+) PHP Object Injection via 'value' Parameter
≤28.2Update to 28.3
- Medium6.8Insecure Direct Object Reference to Authenticated (Subscriber+) Privilege Escalation via 'id' and 'wp_user_id' Parameters via Query String / JSON Body
≤28.4Update to 28.5
- Medium5.3Unauthenticated Sensitive Information Exposure in 'phone' Parameter to bookly_render_details
≤28.4Update to 28.5
- Medium4.3Authenticated (Staff+) Insecure Direct Object Reference
≤28.2Update to 28.3
- Medium5.3Unauthenticated Payment Bypass
≤28.2Update to 28.3
Timeline
CVE published
Severity critical, CVSS 9.1
Record last updated
Sources & licenses
Wordfence record- Vulnerability data
- Wordfence Intelligence. Copyright 2012-2026 Defiant Inc. Licensed under the CC BY-SA 4.0.
- CVE® identifiers
- Copyright 1999-2026 The MITRE Corporation. Used under the CVE Program. CVE® is a registered trademark of The MITRE Corporation.
- CVSS / CWE
- National Vulnerability Database (NVD), shown unmodified. This product uses the NVD API but is not endorsed or certified by the NVD.
- EPSS
- Exploit Prediction Scoring System by FIRST.org.
- VulnCrest content
- Summary, remediation guidance and page layout © VulnCrest. Not sourced from NVD.