CVE-2025-65590 identifies a Cross Site Scripting (XSS) vulnerability in nopCommerce version 4.90.0, a popular open-source e-commerce platform. The vulnerability resides in the Blog posts functionality within the Content Management area, where insufficient input sanitization allows an authenticated user with low privileges to inject malicious JavaScript code. This code can execute in the browsers of other users who view the affected blog content, potentially enabling attackers to steal session cookies, perform actions on behalf of victims, or manipulate displayed content. The CVSS 3.1 vector (AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N) indicates that the attack can be performed remotely over the network with low attack complexity, requires low privileges, and user interaction is necessary. The scope is changed, meaning the vulnerability can affect resources beyond the vulnerable component. The impact affects confidentiality and integrity but not availability. No public exploits have been reported yet, but the vulnerability is published and should be addressed promptly. The lack of an official patch link suggests that vendors or maintainers may not have released a fix at the time of reporting, increasing the urgency for organizations to implement interim mitigations. This vulnerability falls under CWE-79, a common and well-understood class of web application security issues related to improper neutralization of input.

For European organizations, especially those operating e-commerce websites using nopCommerce 4.90.0, this vulnerability poses a risk of client-side script injection that can compromise customer data confidentiality and integrity. Attackers exploiting this XSS flaw could hijack user sessions, steal sensitive information such as login credentials or payment details, and perform unauthorized actions on behalf of users. This undermines customer trust and can lead to regulatory non-compliance under GDPR due to potential data breaches. The vulnerability requires authenticated access with low privileges, which means insider threats or compromised low-level accounts could be leveraged for exploitation. The impact is particularly significant for organizations with high traffic and customer interaction on their blog or content management sections. Additionally, the scope change in the CVSS vector suggests that the vulnerability could affect multiple components or user roles, increasing the potential damage. While availability is not impacted, the reputational and financial consequences of data leakage or fraud can be substantial.

European organizations should immediately audit their nopCommerce installations to identify if version 4.90.0 is in use. In the absence of an official patch, implement strict input validation and output encoding on all user-supplied content within the Blog posts functionality to neutralize malicious scripts. Restrict blog content editing privileges to trusted administrators only, minimizing the risk of malicious input from lower-privileged users. Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts in browsers. Conduct regular security training for content managers to recognize and avoid introducing unsafe content. Monitor web application logs for unusual activities related to blog content submissions. Consider deploying Web Application Firewalls (WAF) with custom rules to detect and block XSS payloads targeting the vulnerable endpoints. Finally, stay alert for vendor updates or patches and apply them promptly once available.