CVE-2026-39680: Diet Calorie Calculator Auth Bypass Flaw

CVE-2026-39680 Overview

CVE-2026-39680 is a Missing Authorization vulnerability affecting the Diet Calorie Calculator WordPress plugin developed by MWP Development. This broken access control flaw allows attackers to exploit incorrectly configured access control security levels, potentially gaining unauthorized access to plugin functionality that should be restricted to authenticated users or administrators.

The vulnerability stems from CWE-862 (Missing Authorization), where the plugin fails to properly verify that users have the necessary permissions before allowing access to certain features or data. This type of flaw can enable unauthenticated attackers to access or manipulate data they should not have permission to view or modify.

Critical Impact

Unauthenticated attackers can exploit missing authorization checks to access restricted plugin functionality, potentially exposing sensitive user diet and calorie tracking data.

Affected Products

• Diet Calorie Calculator WordPress Plugin version 1.1.1 and earlier
• All versions from initial release through 1.1.1

Discovery Timeline

• April 8, 2026 - CVE-2026-39680 published to NVD
• April 8, 2026 - Last updated in NVD database

Technical Details for CVE-2026-39680

Vulnerability Analysis

This Missing Authorization vulnerability occurs because the Diet Calorie Calculator plugin does not implement proper permission checks on certain AJAX endpoints or administrative functions. When a WordPress plugin fails to verify user capabilities before processing requests, any user—including unauthenticated visitors—can potentially invoke privileged functionality.

The vulnerability is exploitable remotely over the network without requiring any user interaction or prior authentication. While the impact is limited to confidentiality concerns with low severity information disclosure, the ease of exploitation (low attack complexity with no prerequisites) makes this a notable security concern for WordPress site administrators.

Root Cause

The root cause of CVE-2026-39680 is the absence of capability checks using WordPress functions like current_user_can() or nonce verification with wp_verify_nonce() before processing sensitive operations. The plugin likely exposes AJAX handlers or REST API endpoints that directly process user requests without first validating that the requesting user has appropriate WordPress capabilities or roles.

In WordPress plugin development, all AJAX callbacks registered with wp_ajax_nopriv_ hooks and REST API endpoints should include explicit authorization checks to ensure only users with appropriate permissions can access the functionality.

Attack Vector

The attack vector for this vulnerability is network-based, meaning an attacker can exploit it remotely without needing local access to the target system. The exploitation process involves:

1. Identifying exposed AJAX endpoints or REST API routes used by the Diet Calorie Calculator plugin
2. Crafting HTTP requests directly to these endpoints, bypassing the normal user interface
3. Accessing data or triggering functionality that should require authentication or specific user roles

The vulnerability can be triggered by sending crafted requests to the vulnerable WordPress installation. For detailed technical information about this vulnerability, refer to the Patchstack Vulnerability Report.

Detection Methods for CVE-2026-39680

Indicators of Compromise

• Unusual HTTP requests to WordPress AJAX endpoints (/wp-admin/admin-ajax.php) referencing Diet Calorie Calculator action hooks
• Unexpected access to plugin-specific REST API routes from unauthenticated sources
• Anomalous patterns of requests to plugin functionality from external IP addresses
• Log entries showing access to restricted plugin features without corresponding user authentication

Detection Strategies

• Monitor web server access logs for requests to admin-ajax.php with action parameters related to the Diet Calorie Calculator plugin
• Implement Web Application Firewall (WAF) rules to detect and alert on suspicious access patterns to WordPress AJAX endpoints
• Review WordPress debug logs for unauthorized access attempts or permission-related errors
• Deploy endpoint detection solutions to monitor for exploitation attempts targeting WordPress plugin vulnerabilities

Monitoring Recommendations

• Enable detailed logging on WordPress installations to capture AJAX request parameters
• Configure alerting for high volumes of requests to plugin-specific endpoints from single IP addresses
• Monitor for reconnaissance activity targeting WordPress plugin enumeration
• Implement rate limiting on AJAX endpoints to slow down automated exploitation attempts

How to Mitigate CVE-2026-39680

Immediate Actions Required

• Update the Diet Calorie Calculator plugin to a patched version as soon as one becomes available from MWP Development
• Review and audit the plugin's presence and necessity on production WordPress installations
• Consider temporarily deactivating the Diet Calorie Calculator plugin until a security patch is released
• Implement WAF rules to restrict access to the vulnerable plugin endpoints

Patch Information

Site administrators should monitor the WordPress plugin repository and the vendor's official channels for security updates addressing this vulnerability. The Patchstack Vulnerability Report provides additional details and may include patch status updates.

Until an official patch is available, implementing the workarounds below can help reduce exposure to this vulnerability.

Workarounds

• Temporarily disable the Diet Calorie Calculator plugin if it is not essential to site operations
• Implement IP-based access restrictions to limit who can reach WordPress AJAX endpoints
• Use a WordPress security plugin to add additional authentication layers to plugin functionality
• Configure the web server or CDN to block requests matching known exploitation patterns

# Apache .htaccess configuration to restrict AJAX access by IP (example)
# Add to WordPress root .htaccess file
<Files admin-ajax.php>
    Order Deny,Allow
    Deny from all
    # Allow your trusted IP addresses
    Allow from 192.168.1.0/24
    Allow from 10.0.0.0/8
</Files>