CVE-2026-42666: Salon Booking System Auth Bypass Issue

CVE-2026-42666 Overview

CVE-2026-42666 is a broken access control vulnerability affecting the Salon booking system WordPress plugin in versions up to and including 10.30.25. The flaw allows unauthenticated attackers to access functionality or data that should require authorization, due to a missing authorization check [CWE-862]. The vulnerability is network-exploitable without user interaction, and successful exploitation impacts the confidentiality of plugin-managed data such as customer bookings and personal information.

Critical Impact
Unauthenticated remote attackers can bypass access controls in the Salon booking system plugin and retrieve sensitive booking data without credentials.

Affected Products

WordPress Salon booking system plugin versions <= 10.30.25
WordPress sites running the affected plugin with default access control configurations
Salon and appointment-based businesses relying on the plugin for customer scheduling

Discovery Timeline

2026-06-15 - CVE-2026-42666 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2026-42666

Vulnerability Analysis

The Salon booking system plugin exposes endpoints or actions that fail to enforce proper authorization before returning data or performing operations. Because the missing check sits in front of functionality intended for authenticated administrators or booking owners, any anonymous client can invoke it. The CWE-862 classification confirms the root issue: the application does not perform an authorization check when a user attempts to access a resource or perform an action.

The vulnerability impacts confidentiality without affecting integrity or availability. Attackers can read protected resources but cannot directly modify or destroy them through this flaw. In WordPress plugin contexts, this pattern typically appears in AJAX handlers or REST routes that omit current_user_can() or capability checks.

Root Cause

The root cause is a missing authorization check on one or more plugin endpoints. The plugin trusts the request itself rather than validating whether the requesting user holds the capability required to access the targeted resource. This violates the principle of complete mediation across plugin entry points.

Attack Vector

An attacker sends crafted HTTP requests directly to the vulnerable plugin endpoint over the network. No authentication, no privileges, and no user interaction are required. Specific endpoint paths and parameters are documented in the Patchstack Vulnerability Advisory.

No verified public proof-of-concept code is available. Refer to the vendor advisory for technical specifics on the affected handlers.

Detection Methods for CVE-2026-42666

Indicators of Compromise

Anonymous HTTP requests to Salon booking system plugin endpoints under /wp-admin/admin-ajax.php or /wp-json/ that return sensitive booking data
Unusual volumes of unauthenticated GET or POST requests targeting plugin-specific actions or REST routes
Access log entries showing repeated enumeration of booking IDs or customer identifiers from a single source

Detection Strategies

Inspect web server access logs for unauthenticated requests to plugin endpoints associated with salon-booking-system
Deploy web application firewall rules that flag access to plugin AJAX or REST handlers without a valid authentication cookie
Correlate plugin response sizes with request patterns to identify data exfiltration attempts via the vulnerable endpoint

Monitoring Recommendations

Enable verbose WordPress logging for REST API and admin-ajax requests targeting the plugin namespace
Alert on bursts of 4xx/2xx responses from plugin endpoints originating from non-browser user agents
Monitor outbound traffic from the web server for unexpected exports of booking or customer records

How to Mitigate CVE-2026-42666

Immediate Actions Required

Update the Salon booking system plugin to a version newer than 10.30.25 as soon as a patched release is published by the vendor
Restrict access to the WordPress site administrative and REST endpoints by IP allowlist where feasible
Audit recent access logs for unauthenticated requests to plugin endpoints to determine if data was exfiltrated

Patch Information

A fixed release addressing the broken access control is referenced in the Patchstack Vulnerability Advisory. Administrators should apply the patched version through the WordPress plugin updater and verify the installed version is above 10.30.25.

Workarounds

Temporarily deactivate the Salon booking system plugin until a patched version is installed
Apply WAF rules that block unauthenticated access to the affected plugin endpoints
Place the WordPress administrative interface behind an authenticated reverse proxy or VPN to reduce exposure

bash

# Example WAF rule to block unauthenticated access to vulnerable plugin endpoints
# Replace <endpoint> with the specific path from the vendor advisory
SecRule REQUEST_URI "@rx /wp-json/salon-booking-system/" \
  "id:1004266,\
   phase:1,\
   deny,\
   status:403,\
   chain,\
   msg:'Block unauthenticated access to Salon booking system endpoint (CVE-2026-42666)'"
  SecRule &REQUEST_COOKIES:wordpress_logged_in_ "@eq 0"