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Bookly Responsive Appointment Booking Tool - Security Vulnerability (CVE-2026-92799)

CVE-2026-92799

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 != ` to evaluate as `false` and the guard to be bypassed.

CVE-2026-92799

MEDIUM CVSS 5.3 Published 2026-09-25 Updated 2026-09-25
AI Risk Elevated (60/100) Active Exploit: No strong signal Published Exploit: No public exploit references Priority: P3 Priority
Severity Band MEDIUM
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Affected Components 3
Reference Links 9
AI Risk Engine Elevated (60/100)
Exploitability High
Active Exploitation No strong signal
Published Exploit Status No public exploit references

Threat Timeline

  1. 2026-09-25 CVE published and first recorded in the threat feed.
  2. 2026-09-25 Record updated with latest vulnerability metadata.
  3. 2026-10-01 AI technical context refreshed for mitigation and impact guidance.
  4. Now Monitoring for follow-up changes, linked references, and new related CVEs.

AI Context

Machine-generated threat intelligence

AI Updated 9 days ago

AI enriched 9 days ago (2026-10-01 06:33 UTC)

Technical Summary

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…

Potential Impact

Severity is MEDIUM (CVSS 5.3). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.

Exploitability Assessment

Exploitability is assessed as High based on remote code execution potential, low-bar exploit prerequisites.

Primary risk drivers: remote code execution potential, low-bar exploit prerequisites

Mitigation Recommendations

Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.

Detection & Monitoring

Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.

Business Impact Lens

AI risk score 60/100 (Elevated, High) with priority P3 Priority. Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.

Affected Products

Bookly Responsive Appointment Booking Tool PLUGIN · bookly-responsive-appointment-booking-tool Affected: >= 0, <= 28.2 Fixed version not specified
Online Scheduling and Appointment Booking System PLUGIN · online-scheduling-and-appointment-booking-system Affected: >= 0, <= 28.2 Fixed version not specified
Online Scheduling and Appointment Booking System – Bookly PLUGIN · online-scheduling-and-appointment-booking-system-bookly Affected: >= 0, <= 28.2 Fixed version not specified

References

What to do about this

Patch promptly The consequence is significant even where an attacker needs a foothold first.

Fix it

Update Bookly Responsive Appointment Booking Tool to the latest available version.

Where the vendor has not published a fix yet, disable the plugin until they do.

Cannot update today? Request / payload inspection (WAF) in Hack Halt ProSecure blocks this class of attack before WordPress processes the request.

Inspect request parameters and bodies for injection, traversal and file-inclusion payloads, and refuse the request rather than logging it.

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Not sure if you are affected?

Scan your site to see whether it runs Bookly Responsive Appointment Booking Tool, and at which version.

Free, no installation, no account. It reads what your site already publishes, then tells you which plugins carry known vulnerabilities and what to do about each one.

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Am I affected by this vulnerability?

You are affected if your site runs Bookly Responsive Appointment Booking Tool. No account is needed to exploit this, so a public site is reachable by anyone.

How do I fix it?

Update Bookly Responsive Appointment Booking Tool to the latest available version. Where the vendor has not yet published a fix, remove or disable the plugin until they do. Until you can update, Request / payload inspection (WAF) in Hack Halt ProSecure contains this class of attack at the request layer.

What can an attacker actually do?

This is a Broken Access Control flaw. An attacker who exploits it can reach actions or data that should have been restricted to someone else.