What the vulnerability does
01Description
The Piraeus Bank WooCommerce Payment Gateway plugin for WordPress is vulnerable to unauthorized order status modification in all versions up to, and including, 3.1.4. This is due to missing authorization checks on the payment callback endpoint handler when processing the 'fail' callback from the payment gateway. This makes it possible for unauthenticated attackers to change any order's status to 'failed' via the publicly accessible WooCommerce API endpoint by providing only the order ID (MerchantReference parameter), which can be easily enumerated as order IDs are sequential integers. This can cause significant business disruption including canceled shipments, inventory issues, and loss of revenue.
Explanation of Vulnerability in Simple Terms
02Summary
The Piraeus Bank WooCommerce Payment Gateway plugin through version 3.1.4 lacks proper authorization checks, allowing unauthenticated attackers to modify payment-related data via network requests. No user interaction is required. The vulnerability affects the integrity of payment transactions but does not expose sensitive data or disrupt service availability.
What an attacker can do
03Attacker Capabilities
Modify payment transaction data without authentication.
Potential impact on your site
04Site Impact
Payment records or transaction details could be altered by unauthorized parties, potentially affecting order accuracy and financial reconciliation.
Conditions required to exploit
05Prerequisites
Network access to the WordPress site; no authentication or user interaction required.
Key dates
06Disclosure timeline
January 7, 2026
CVE published
April 8, 2026
Record updated
