CVE-2026-40795: Amelia Auth Bypass Vulnerability

CVE-2026-40795 Overview

CVE-2026-40795 is a broken access control vulnerability affecting the Amelia booking plugin for WordPress in versions up to and including 2.2. The flaw allows authenticated users with subscriber-level privileges to perform actions that should be restricted to higher-privileged roles. The vulnerability is categorized as a missing authorization issue [CWE-862], where the plugin fails to verify whether the requesting user has permission to perform sensitive operations. Successful exploitation can lead to unauthorized modification of booking data and other integrity impacts within the affected WordPress installation.

Critical Impact
Authenticated subscriber-level attackers can bypass access controls in the Amelia plugin to manipulate restricted resources, resulting in high integrity impact on affected WordPress sites.

Affected Products

Amelia WordPress Booking Plugin versions <= 2.2
WordPress sites with the ameliabooking plugin installed and active
Deployments allowing subscriber-level user registration

Discovery Timeline

2026-06-15 - CVE-2026-40795 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2026-40795

Vulnerability Analysis

The vulnerability resides in the Amelia booking plugin for WordPress, a widely deployed appointment and event booking solution. The plugin exposes functionality that does not properly verify the authorization level of the requesting user. An attacker with only subscriber privileges, which is the lowest authenticated role in WordPress and is often granted automatically during user registration, can invoke restricted operations through the plugin's endpoints.

The Common Weakness Enumeration classification [CWE-862] indicates that the application performs an action without verifying that the actor has appropriate permissions. In the context of Amelia, this enables manipulation of booking records, customer data, or configuration settings that should require administrator or manager roles.

Root Cause

The root cause is the absence of capability checks on plugin actions or AJAX handlers. WordPress plugins are expected to validate user capabilities using functions such as current_user_can() before performing privileged operations. In Amelia <= 2.2, certain handlers accept and process requests from any authenticated user without enforcing role-based restrictions, allowing subscribers to access functionality intended only for elevated roles.

Attack Vector

Exploitation requires network access and a valid subscriber account on the target WordPress site. The attacker authenticates and issues crafted HTTP requests directly to the plugin's vulnerable endpoints. Because user interaction is not required and the attack complexity is low, automated tooling can mass-exploit vulnerable installations once endpoint details become public. Refer to the Patchstack WordPress Vulnerability Report for additional technical context.

Detection Methods for CVE-2026-40795

Indicators of Compromise

Unexpected modifications to bookings, appointments, services, or customer records within Amelia database tables
Authenticated HTTP requests to Amelia plugin endpoints originating from subscriber accounts
New or unfamiliar subscriber accounts created shortly before suspicious plugin activity
WordPress audit log entries showing privileged actions attributed to low-privilege users

Detection Strategies

Inspect web server access logs for POST requests to admin-ajax.php containing Amelia-specific action parameters from non-administrator sessions
Correlate WordPress user role data with the user IDs executing Amelia administrative actions
Enable WordPress audit logging plugins to capture capability-sensitive operations and flag anomalies

Monitoring Recommendations

Monitor for spikes in subscriber registrations followed by Amelia plugin API calls
Alert on database changes to Amelia tables from accounts lacking manager or administrator roles
Track outbound notifications or email triggers generated by booking modifications from unusual users

How to Mitigate CVE-2026-40795

Immediate Actions Required

Update the Amelia plugin to the latest patched version released after 2.2 as referenced in the Patchstack advisory
Audit all WordPress user accounts and remove or disable unnecessary subscriber accounts
Review Amelia booking, customer, and configuration data for unauthorized changes since the plugin's installation

Patch Information

The vendor has addressed the issue in a release subsequent to version 2.2. Administrators should consult the Patchstack WordPress Vulnerability Report for the fixed version and apply the update through the WordPress plugin manager or by replacing plugin files manually.

Workarounds

Disable open user registration in WordPress settings to prevent attackers from obtaining subscriber accounts
Restrict access to wp-admin/admin-ajax.php for non-administrator users via a web application firewall rule
Temporarily deactivate the Amelia plugin on sites that cannot apply the patch immediately

bash

# Disable open registration via wp-config.php or wp-cli
wp option update users_can_register 0

# Verify Amelia plugin version
wp plugin get ameliabooking --field=version

# Update Amelia to the patched release
wp plugin update ameliabooking