CVE-2025-59411 is a medium-severity Cross-Site Scripting (XSS) vulnerability identified in CubeCart version 6, an ecommerce software platform. The vulnerability exists in versions prior to 6.5.11, specifically in the contact form's Enquiry field. This field improperly accepts raw HTML input from users without sanitization or escaping. When a user submits HTML content in the Enquiry field, this content is included verbatim in the email sent to the store administrator. This behavior indicates that user input is not neutralized before being output in emails, and potentially when re-rendering the form in the admin interface. As a result, malicious actors can inject HTML or JavaScript code that could execute in the context of the email client or the admin UI, leading to XSS or HTML injection attacks. Such attacks can be used to steal session cookies, perform phishing, or execute arbitrary scripts in the administrator's environment. The vulnerability has been addressed and patched in CubeCart version 6.5.11. The CVSS 3.1 base score is 5.4, reflecting a medium severity level. The vector indicates that the attack can be performed remotely over the network without privileges, requires user interaction (the admin opening the malicious email), and impacts confidentiality and integrity but not availability. There are no known exploits in the wild at this time.

For European organizations using CubeCart ecommerce software versions prior to 6.5.11, this vulnerability poses a risk primarily to the confidentiality and integrity of administrative communications. Successful exploitation could allow attackers to execute malicious scripts within the administrator's email client or admin UI, potentially leading to credential theft, session hijacking, or unauthorized actions within the ecommerce platform. This could result in unauthorized access to sensitive customer data, manipulation of orders, or disruption of ecommerce operations. Given the ecommerce context, such breaches could damage customer trust, lead to regulatory non-compliance under GDPR due to data exposure, and cause financial losses. The risk is heightened if administrators frequently access contact form submissions via email clients that render HTML content without sufficient security controls. However, the attack requires the administrator to interact with the malicious email, which somewhat limits the scope of exploitation.

European organizations should immediately upgrade CubeCart installations to version 6.5.11 or later, where this vulnerability is patched. Until the upgrade is applied, administrators should be advised to treat contact form enquiry emails with caution, avoiding opening or interacting with suspicious or unexpected messages. Email clients used by administrators should be configured to disable automatic HTML rendering or scripting in emails, or to display emails in plain text mode to reduce XSS risk. Implementing email filtering solutions that sanitize incoming emails or flag suspicious content can further reduce exposure. Additionally, organizations should review and harden the CubeCart contact form input validation and output encoding settings if customization is possible. Monitoring administrative accounts for unusual activity and ensuring strong authentication mechanisms are in place will help mitigate potential exploitation consequences. Finally, conducting security awareness training for administrators about phishing and XSS risks related to email content is recommended.