Online Scheduling and Appointment Booking System <= 28.2 — Unauthenticated Authorization Bypass via PHP Type Juggling via 'verification_code' Parameter Type Juggling via json_data
CVE-2026-92799Published · Updated Action summary
Affected: ≤28.2Update to 28.3 or newer
All remediation steps- Severity
- Medium5.3
- CVSS
- 5.3CVSS 3.1 · CNA (Wordfence)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NWhat 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:LIntegrity- Low
A:NAvailability- None
- Weakness
- CWE-285 Improper Authorization
- Required access
- No account needed
- Exploit prediction (EPSS)
- 0.4% chance in 30 days30th 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 crow.
The Online Scheduling and Appointment Booking System – Bookly plugin for WordPress is vulnerable to Authorization Bypass via PHP Type Juggling in all versions up to, and including, 28.2. This is due to the `postValidateCustomer()` function using a loose PHP inequality operator (`!=`) to compare the session-stored one-time verification code against the attacker-supplied `verification_code` parameter — a flaw that is further exposed by the booking AJAX controller registering all its methods as `wp_ajax_nopriv_` handlers and unconditionally overriding `csrfTokenValid()` to return true, leaving the endpoint both unauthenticated and CSRF-unprotected. This makes it possible for unauthenticated attackers to bypass the phone/email ownership verification step and overwrite the name, email, phone, and address fields of any arbitrary existing Bookly customer record, redirecting that customer's booking notifications to attacker-controlled contact details. The bypass is achievable because the `json_data` input channel decodes input via `json_decode()`, which preserves real PHP types and causes the `wp_kses` filter to leave non-string values such as the JSON boolean `true` untouched; submitting `true` as the `verification_code` satisfies the loose comparison against the session's non-zero integer code (generated by `mt_rand(100000, 999999)`), causing `true != <non-zero int>` to evaluate as `false` and the guard to be bypassed.
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 medium, CVSS 5.3
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.