CVE-2026-39672: ShipTime Plugin Auth Bypass Vulnerability

CVE-2026-39672 Overview

A Missing Authorization vulnerability has been identified in the ShipTime: Discounted Shipping Rates WordPress plugin (shiptime-discount-shipping). This broken access control flaw allows attackers to exploit incorrectly configured access control security levels, potentially exposing sensitive shipping configuration data to unauthorized users.

Critical Impact

Unauthenticated attackers can bypass authorization checks to access restricted functionality or sensitive information within the ShipTime plugin without proper credentials.

Affected Products

• ShipTime: Discounted Shipping Rates WordPress Plugin versions up to and including 1.1.1
• WordPress installations running the vulnerable shiptime-discount-shipping plugin

Discovery Timeline

• 2026-04-08 - CVE-2026-39672 published to NVD
• 2026-04-08 - Last updated in NVD database

Technical Details for CVE-2026-39672

Vulnerability Analysis

This vulnerability falls under CWE-862 (Missing Authorization), a common security weakness where the application fails to perform authorization checks before allowing access to protected resources or functionality. In the context of the ShipTime plugin, specific AJAX handlers or API endpoints likely lack proper capability checks, allowing unauthenticated or low-privileged users to access administrative functions.

The network-accessible nature of this vulnerability means attackers can exploit it remotely without requiring any user interaction. While the impact is limited to information disclosure rather than full system compromise, exposed shipping configurations could reveal sensitive business data including API credentials, shipping rates, or customer information.

Root Cause

The root cause is a failure to implement proper authorization checks (such as WordPress current_user_can() capability checks or nonce verification) on plugin endpoints that should be restricted to authenticated administrators. This is a common pattern in WordPress plugin vulnerabilities where developers register AJAX actions or REST API endpoints without adequate access control validation.

Attack Vector

The attack vector is network-based, requiring no authentication, no user interaction, and low complexity to exploit. An attacker can directly access vulnerable plugin endpoints by crafting HTTP requests to the WordPress installation. The attack flow typically involves:

1. Identifying the target WordPress site running the vulnerable ShipTime plugin
2. Discovering unprotected AJAX actions or REST API endpoints exposed by the plugin
3. Sending crafted requests to these endpoints without authentication
4. Receiving unauthorized access to plugin functionality or sensitive data

Since no verified code examples are available for this vulnerability, readers should consult the Patchstack Vulnerability Report for detailed technical analysis of the specific vulnerable code paths.

Detection Methods for CVE-2026-39672

Indicators of Compromise

• Unusual HTTP requests to ShipTime plugin AJAX handlers from unauthenticated sources
• Access log entries showing requests to /wp-admin/admin-ajax.php with ShipTime-related action parameters from external IPs
• Unexpected access to shipping configuration data or API endpoints without corresponding admin login sessions

Detection Strategies

• Monitor WordPress access logs for requests to AJAX endpoints containing shiptime action parameters from unauthenticated sessions
• Implement Web Application Firewall (WAF) rules to detect and block suspicious access patterns targeting the ShipTime plugin
• Review WordPress audit logs for unauthorized access attempts to shipping-related functionality
• Scan WordPress installations for the presence of vulnerable plugin versions using security scanning tools

Monitoring Recommendations

• Enable detailed logging for WordPress AJAX requests and monitor for anomalous patterns
• Configure alerts for any access to ShipTime plugin endpoints from non-administrative users
• Implement rate limiting on plugin AJAX handlers to slow potential enumeration attacks
• Regularly audit plugin configurations and access logs for signs of unauthorized access

How to Mitigate CVE-2026-39672

Immediate Actions Required

• Update the ShipTime: Discounted Shipping Rates plugin to a patched version as soon as one becomes available
• Temporarily deactivate the shiptime-discount-shipping plugin if not immediately required for business operations
• Implement Web Application Firewall rules to restrict access to ShipTime plugin endpoints
• Review access logs for any indication of prior exploitation attempts

Patch Information

At the time of publication, administrators should monitor the WordPress plugin repository and the Patchstack Vulnerability Report for updated versions that address this vulnerability. Update to a version greater than 1.1.1 when available.

Workarounds

• Restrict access to WordPress admin AJAX endpoints at the web server level using IP-based allowlists
• Implement a WAF rule to block unauthenticated requests to ShipTime-related AJAX actions
• Temporarily disable the plugin until a patched version is released
• Use WordPress security plugins that can enforce additional capability checks on AJAX handlers

# Example .htaccess rule to restrict AJAX access (Apache)
# Add to WordPress root .htaccess file
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{REQUEST_URI} ^/wp-admin/admin-ajax\.php
RewriteCond %{QUERY_STRING} action=shiptime [NC]
RewriteCond %{HTTP_COOKIE} !wordpress_logged_in
RewriteRule .* - [F,L]
</IfModule>