CVE-2025-66071 is a critical security vulnerability identified in the Custom Order Numbers for WooCommerce plugin developed by tychesoftwares. The issue stems from missing authorization checks within the plugin, which allows unauthenticated attackers to exploit improperly configured access control mechanisms. Specifically, this vulnerability enables attackers to manipulate or access order number data without proper permissions, potentially altering order records or interfering with order processing workflows. The affected versions include all releases up to and including version 1.11.0. The vulnerability has been assigned a CVSS 3.1 base score of 9.8, reflecting its critical nature. The vector metrics indicate that the attack can be performed remotely over the network (AV:N), requires no privileges (PR:N), no user interaction (UI:N), and impacts confidentiality, integrity, and availability (C:H/I:H/A:H). This means an attacker can fully compromise order data and disrupt e-commerce operations without any authentication barriers. Although no public exploits have been reported yet, the vulnerability's characteristics suggest it could be weaponized easily. The plugin is widely used in WooCommerce installations, a popular e-commerce platform, making the threat relevant to many online retailers. The missing authorization flaw could lead to fraudulent order manipulation, data leakage, or denial of service conditions affecting order management. The vulnerability was published on November 21, 2025, and no patches or fixes have been linked yet, emphasizing the need for vigilance and proactive mitigation.

For European organizations, this vulnerability poses a significant risk to the integrity and availability of e-commerce operations. Attackers exploiting this flaw can manipulate order numbers, potentially leading to financial fraud, inventory mismanagement, or disruption of customer transactions. The confidentiality of order-related data could also be compromised, exposing sensitive customer information and violating data protection regulations such as GDPR. The critical CVSS score indicates that exploitation could result in complete compromise of order processing systems without requiring authentication, increasing the likelihood of widespread abuse. Given the reliance on WooCommerce by many small to medium-sized enterprises across Europe, the impact could be substantial, affecting revenue, customer trust, and regulatory compliance. Additionally, disruption of order workflows could lead to operational downtime and increased support costs. The absence of known exploits in the wild currently provides a small window for remediation, but the high severity demands immediate attention.

Organizations should immediately inventory their WooCommerce installations to identify if the Custom Order Numbers for WooCommerce plugin is in use and verify the version. Until a patch is released, consider disabling or removing the plugin to eliminate the attack surface. Implement strict web application firewall (WAF) rules to monitor and block suspicious requests targeting order number management endpoints. Enhance logging and monitoring around order management activities to detect anomalous behavior indicative of exploitation attempts. Restrict access to WooCommerce administrative interfaces using IP whitelisting or VPNs to reduce exposure. Engage with the vendor (tychesoftwares) for timely updates and apply patches as soon as they become available. Conduct penetration testing focused on authorization controls in e-commerce workflows to uncover similar weaknesses. Educate staff on the risks and signs of order manipulation attacks to improve incident response readiness. Finally, review and strengthen overall access control policies within the e-commerce environment to prevent privilege escalation.