CVE-2025-65590 identifies a Cross Site Scripting (XSS) vulnerability in nopCommerce version 4.90.0, specifically within the Blog posts functionality of the Content Management system. XSS vulnerabilities occur when an application does not properly sanitize user-supplied input, allowing attackers to inject malicious scripts that execute in the browsers of other users. In this case, the vulnerability resides in the blog post feature, which likely accepts user input for content creation or editing without adequate filtering or encoding. Exploiting this flaw, an attacker could craft malicious blog content that, when viewed by administrators or other users, executes arbitrary JavaScript code. This can lead to session hijacking, theft of authentication tokens, redirection to malicious sites, or unauthorized actions performed on behalf of the victim. nopCommerce is a popular open-source e-commerce platform used globally, including in Europe, for managing online stores and content. The vulnerability was reserved in November 2025 and published in December 2025, but no CVSS score or patches are currently available, and no known exploits have been reported in the wild. Despite this, the risk remains significant due to the common impact of XSS vulnerabilities and the critical nature of the affected functionality. The absence of a CVSS score requires an assessment based on the vulnerability's characteristics: it impacts confidentiality and integrity, is relatively easy to exploit without authentication or user interaction beyond viewing the malicious content, and affects a widely deployed platform. Therefore, it is assessed as high severity. Organizations using nopCommerce 4.90.0 should monitor for patches, review input validation mechanisms, and consider additional protective controls such as Content Security Policy (CSP) to mitigate potential exploitation.

The primary impact of this XSS vulnerability is on the confidentiality and integrity of user sessions and data within nopCommerce installations. An attacker exploiting this flaw can execute arbitrary scripts in the context of users who view the malicious blog posts, potentially leading to session hijacking, credential theft, or unauthorized actions such as changing content or performing administrative tasks. For European organizations, especially those operating e-commerce platforms with public-facing blogs or content management features, this can result in customer data compromise, reputational damage, financial losses, and regulatory penalties under GDPR due to data breaches. The vulnerability could also be leveraged as a foothold for further attacks within the network or to distribute malware to visitors. Although availability is less directly impacted, the trustworthiness and integrity of the platform are severely undermined. The lack of known exploits in the wild provides a window for proactive mitigation, but the widespread use of nopCommerce in Europe means the potential attack surface is significant. Organizations failing to address this vulnerability risk targeted attacks that could disrupt business operations and customer trust.

1. Monitor official nopCommerce channels for patches or updates addressing CVE-2025-65590 and apply them promptly once available. 2. Implement strict input validation and output encoding on all user-supplied content within the Blog posts functionality to prevent script injection. 3. Employ Content Security Policy (CSP) headers to restrict the execution of untrusted scripts and reduce the impact of potential XSS attacks. 4. Conduct regular security audits and code reviews focusing on content management features to identify and remediate similar vulnerabilities. 5. Educate content creators and administrators about the risks of injecting untrusted content and enforce safe content publishing practices. 6. Use web application firewalls (WAF) with rules designed to detect and block XSS attack patterns targeting nopCommerce. 7. Limit administrative access to the content management area using multi-factor authentication and role-based access controls to reduce the risk of exploitation. 8. Regularly back up website data and configurations to enable quick recovery in case of compromise. 9. Monitor logs and user activity for unusual behavior indicative of exploitation attempts. 10. Consider deploying runtime application self-protection (RASP) solutions to detect and block XSS attacks in real time.