CVE-2026-59528: ShipTime Data Exposure Vulnerability

CVE-2026-59528 Overview

CVE-2026-59528 is a sensitive data exposure vulnerability in the ShipTime: Discounted Shipping Rates WordPress plugin, affecting versions up to and including 1.1.1. The flaw allows authenticated users with subscriber-level privileges to access sensitive information that should be restricted. The issue is classified under CWE-497: Exposure of Sensitive System Information to an Unauthorized Control Sphere. Attackers can exploit the vulnerability remotely over the network without user interaction.

Critical Impact
Low-privilege subscriber accounts can retrieve sensitive plugin data intended for administrators, exposing configuration or account information tied to shipping integrations.

Affected Products

ShipTime: Discounted Shipping Rates WordPress plugin
All versions less than or equal to 1.1.1
WordPress sites with the plugin installed and subscriber registration enabled

Discovery Timeline

2026-07-27 - CVE-2026-59528 published to the National Vulnerability Database
2026-07-27 - Last updated in NVD database

Technical Details for CVE-2026-59528

Vulnerability Analysis

The ShipTime: Discounted Shipping Rates plugin exposes sensitive information to users holding the WordPress subscriber role. Subscriber accounts represent the lowest authenticated privilege tier in WordPress and are commonly granted through open registration. The plugin fails to enforce sufficient capability checks before returning data intended for administrators or store operators. An attacker with any authenticated session can therefore retrieve configuration data, API-related values, or other information the plugin manages.

The EPSS score of 0.398% places exploitation probability in the lower percentile band, but the low authentication barrier makes opportunistic abuse feasible on sites permitting user registration. The Patchstack advisory confirms the affected version range and classifies the issue as sensitive data exposure.

Root Cause

The root cause is missing or insufficient authorization enforcement on plugin endpoints or handlers that return sensitive data. The plugin does not restrict access based on required WordPress capabilities such as manage_options or manage_woocommerce. Any authenticated user, including subscribers, can invoke the affected code paths and receive protected data. This maps to CWE-497, where sensitive system information reaches an unauthorized control sphere.

Attack Vector

Exploitation requires network access to the target WordPress site and a valid subscriber account. On sites with open registration or WooCommerce customer signup, an attacker can self-provision the required account. Once authenticated, the attacker issues a request to the vulnerable plugin endpoint and receives the sensitive response payload. No user interaction, elevated privileges, or social engineering is required.

For technical exploitation specifics, refer to the Patchstack Vulnerability Report.

Detection Methods for CVE-2026-59528

Indicators of Compromise

Unexpected authenticated requests from subscriber accounts to /wp-admin/admin-ajax.php or plugin REST routes tied to ShipTime
New subscriber account registrations followed shortly by plugin-related endpoint access
Outbound data flows or log entries showing plugin responses containing configuration or credential-like values delivered to non-administrator users

Detection Strategies

Audit WordPress access logs for requests to ShipTime plugin endpoints originating from users without administrative roles
Correlate user role metadata with request patterns to identify subscribers invoking privileged plugin actions
Deploy Web Application Firewall rules that flag authenticated access to plugin AJAX or REST handlers by low-privilege users

Monitoring Recommendations

Enable verbose logging on wp-admin/admin-ajax.php and plugin REST namespaces for the ShipTime plugin
Alert on newly created subscriber accounts followed by immediate plugin endpoint interaction within a short time window
Monitor for outbound HTTP responses containing keywords associated with the plugin's sensitive configuration fields

How to Mitigate CVE-2026-59528

Immediate Actions Required

Update the ShipTime: Discounted Shipping Rates plugin to a version above 1.1.1 once released by the vendor
Disable open user registration in WordPress settings until the plugin is patched
Audit existing subscriber accounts and remove any that are not required for site operation
Rotate any credentials, API keys, or tokens configured in the plugin that may have been exposed

Patch Information

At the time of publication, no fixed version is listed in the enriched CVE data. Site operators should monitor the Patchstack Vulnerability Report and the plugin's official update channel for a patched release. Apply the update to all WordPress instances hosting the plugin as soon as it becomes available.

Workarounds

Deactivate and remove the ShipTime: Discounted Shipping Rates plugin until a fixed version is available
Restrict access to the WordPress login and registration pages using IP allowlisting or a Web Application Firewall
Set the default new user role in WordPress settings to a value that limits authenticated access, and disable self-registration where possible
Apply virtual patching rules via a WAF to block requests to the vulnerable plugin endpoints from non-administrator sessions

bash

# Disable open WordPress user registration via wp-cli
wp option update users_can_register 0

# Deactivate the vulnerable plugin until a fix is released
wp plugin deactivate shiptime-discount-shipping