CVE-2026-17589: WordPress Shopping Cart Plugin SQLi Flaw

CVE-2026-17589 Overview

CVE-2026-17589 is a second-order SQL injection vulnerability [CWE-89] in the Shopping Cart & eCommerce Store plugin for WordPress, affecting all versions up to and including 5.9.2. Attackers with administrator-level access can inject SQL through the product_order parameter due to insufficient escaping and improper query preparation. The payload is stored in the ec_pageoption table through the ec_ajax_save_page_options handler, then later retrieved and concatenated directly into SQL on every store page render. This allows authenticated attackers to extract sensitive data from the database.

Critical Impact

Authenticated administrators can execute arbitrary SQL queries against the WordPress database, exposing credentials, customer records, and other stored data.

Affected Products

• Shopping Cart & eCommerce Store plugin for WordPress (wp-easycart)
• All versions up to and including 5.9.2
• WordPress sites running the vulnerable plugin regardless of theme configuration

Discovery Timeline

• 2026-09-01 - CVE-2026-17589 published to NVD
• 2026-09-01 - Last updated in NVD database

Technical Details for CVE-2026-17589

Vulnerability Analysis

The vulnerability is a second-order SQL injection in the WP EasyCart plugin. The injection is not exploited at the initial request. Instead, the attacker first writes a malicious payload to persistent storage, and the payload triggers when the application later reads and uses that data in a SQL query.

The attack surface exists in the product_order parameter processed by the store filter logic in ec_filter.php. Administrator-level attackers can persist crafted SQL fragments into the database. These fragments then execute unsanitized on every store page render, enabling data extraction across the WordPress schema.

Root Cause

Two defects combine to enable exploitation. First, the ec_ajax_save_page_options handler writes raw $_POST values into the ec_pageoption table without applying sanitization or parameterization. Second, when the plugin later retrieves the stored value, it calls stripslashes() on the data before concatenating it into a SQL query. That call strips the escaping that WordPress magic-quotes protection would normally apply, restoring the original injection payload intact.

The resulting query is built through string concatenation rather than a prepared statement, so any SQL syntax embedded in product_order is executed by the database.

Attack Vector

Exploitation requires authenticated administrator or higher privileges. The attacker submits a payload to the AJAX save handler that stores their crafted product_order value. On subsequent renders of any affected store page, the plugin reads the stored value, removes escaping via stripslashes(), and appends it to a live query. The attacker can then extract database contents through the resulting UNION-style or boolean-based extraction paths.

The vulnerability manifests in the filter and rendering code paths documented in the WordPress Plugin Filter Code and the WordPress Plugin Main File Code. See the referenced advisories rather than a synthetic payload example.

Detection Methods for CVE-2026-17589

Indicators of Compromise

• Unexpected SQL syntax such as UNION, SELECT, or comment markers stored in rows of the ec_pageoption table.
• Anomalous admin-ajax.php requests invoking the ec_ajax_save_page_options action from administrator sessions.
• Database error entries or long-running queries generated during rendering of store pages.
• Access to sensitive tables such as wp_users or wp_usermeta originating from the store rendering process.

Detection Strategies

• Inspect the ec_pageoption table for stored values containing SQL keywords, quote characters, or encoded payloads in the product_order field.
• Review web server and WordPress audit logs for POST requests to ec_ajax_save_page_options and correlate with subsequent store page renders.
• Enable and monitor MySQL general query or slow query logs for queries containing the product_order context that reference unexpected tables.

Monitoring Recommendations

• Alert on administrator account activity that modifies plugin option tables outside of normal maintenance windows.
• Track new or modified rows in ec_pageoption and require review before accepting values with non-alphanumeric characters.
• Baseline the SQL query patterns emitted by the plugin so that deviations trigger investigation.

How to Mitigate CVE-2026-17589

Immediate Actions Required

• Update the Shopping Cart & eCommerce Store plugin to a version later than 5.9.2 as soon as the vendor releases a fixed build.
• Restrict administrator accounts to trusted personnel and enforce multi-factor authentication on those accounts.
• Audit the ec_pageoption table for stored payloads and remove any entries containing SQL syntax in product_order.

Patch Information

Refer to the WordPress Changeset Overview and the Wordfence Vulnerability Report for the fix commit and the affected code locations. The remediation removes the stripslashes() call and enforces proper preparation of the product_order value before it reaches the SQL layer.

Workarounds

• Temporarily deactivate the WP EasyCart plugin on production sites until the patched version is applied.
• Place a web application firewall rule in front of admin-ajax.php to block ec_ajax_save_page_options requests containing SQL metacharacters in product_order.
• Reduce the number of accounts with administrator or higher privileges to limit the exploitation surface.
• Restore the ec_pageoption table from a known-clean backup if stored payloads are detected.