CVE-2025-52036 is a stored Cross-Site Scripting (XSS) vulnerability identified in the NotesCMS content management system. The vulnerability specifically affects the /index.php?route=categories page, where the manipulation of the title of service descriptions allows an attacker to inject malicious scripts that are stored on the server and later executed in the browsers of users who visit the affected page. This vulnerability was confirmed in the source code as of commit 7d821a0f028b0778b245b99ab3d3bff1ac10e2d3 dated May 8, 2024, and was fixed in commit 95322c5121dbd7070f3bd54f2848079654a0a8ea on March 31, 2025. The vulnerability is classified under CWE-79, which covers improper neutralization of input leading to XSS. The attack can be launched remotely without requiring authentication or user interaction to inject the payload, but user interaction is needed to trigger the malicious script execution when a victim visits the compromised page. Stored XSS vulnerabilities are particularly dangerous because the malicious payload persists on the server and can affect multiple users. This vulnerability could allow attackers to steal session cookies, perform actions on behalf of users, deface websites, or deliver malware. There is no CVSS score assigned yet, and no known exploits in the wild have been reported as of the publication date August 26, 2025.

For European organizations using NotesCMS, this vulnerability poses a significant risk to the confidentiality and integrity of user data and the availability of services. Attackers exploiting this flaw could hijack user sessions, leading to unauthorized access to sensitive information or administrative functions. This could result in data breaches, reputational damage, and potential regulatory penalties under GDPR if personal data is compromised. The stored nature of the XSS means that multiple users could be affected over time, increasing the scope of impact. Additionally, attackers could use the vulnerability to distribute malware or conduct phishing campaigns by injecting malicious scripts that alter website content. Organizations relying on NotesCMS for public-facing websites or internal portals are particularly at risk, as the vulnerability affects a commonly accessed page (/index.php?route=categories). The remote exploitability without authentication increases the threat level, especially for organizations with limited web application security controls or insufficient input validation and output encoding practices.

To mitigate this vulnerability, European organizations should immediately apply the patch introduced in commit 95322c5121dbd7070f3bd54f2848079654a0a8ea dated March 31, 2025. If patching is not immediately possible, organizations should implement strict input validation and output encoding on the title fields of service descriptions to neutralize any injected scripts. Employing Content Security Policy (CSP) headers can help reduce the impact by restricting the execution of unauthorized scripts. Web Application Firewalls (WAFs) configured to detect and block XSS payloads can provide temporary protection. Regular security audits and code reviews focusing on input handling and sanitization are recommended to prevent similar issues. User awareness training to recognize suspicious website behavior can help mitigate the risk of successful exploitation. Finally, monitoring logs for unusual activity on the affected page can aid in early detection of exploitation attempts.