CVE-2025-52486 is a cross-site scripting (XSS) vulnerability affecting the Dnn.Platform content management system (CMS), an open-source platform widely used within the Microsoft ecosystem. The vulnerability exists in versions 6.0.0 up to but not including 10.0.1. It arises from improper neutralization of input during web page generation, specifically when using the TokenReplace feature combined with certain SkinObjects. Attackers can craft malicious content embedded in URLs that, when processed by the vulnerable versions of Dnn.Platform, are not properly sanitized. This allows the injection and execution of arbitrary JavaScript code in the context of the victim's browser. The vulnerability does not require authentication and can be exploited remotely via a network vector, with low attack complexity and no privileges required. However, user interaction is necessary, as the victim must visit a crafted URL. The vulnerability does not affect confidentiality, integrity, or availability directly but can lead to session hijacking, credential theft, or other client-side attacks, potentially compromising user accounts or enabling further exploitation. The issue has been addressed in version 10.0.1 of Dnn.Platform, which properly sanitizes input in the affected components. No known exploits are currently in the wild, but the medium CVSS score of 6.1 reflects the moderate risk posed by this vulnerability given its ease of exploitation and potential impact on user security.

For European organizations using Dnn.Platform versions prior to 10.0.1, this vulnerability poses a significant risk to web application security. Successful exploitation can lead to the execution of malicious scripts in users' browsers, enabling theft of session cookies, redirection to phishing sites, or delivery of malware. This can compromise user accounts, including administrative users, leading to unauthorized access or data exposure. Organizations in sectors with high web presence—such as government, finance, healthcare, and e-commerce—may face reputational damage, regulatory penalties under GDPR for inadequate protection of user data, and operational disruptions. Since the vulnerability requires user interaction, the risk is amplified in environments with high user traffic or where users are less security-aware. Additionally, the Microsoft ecosystem integration means that organizations relying on Dnn.Platform for intranet or extranet portals could see lateral movement or privilege escalation attempts if attackers leverage stolen credentials or session tokens. The lack of known exploits currently provides a window for proactive patching and mitigation to prevent potential attacks.

1. Immediate upgrade to Dnn.Platform version 10.0.1 or later, where the vulnerability is patched, is the most effective mitigation. 2. Implement Web Application Firewall (WAF) rules specifically targeting suspicious URL patterns and script injection attempts related to TokenReplace and SkinObjects usage. 3. Conduct a thorough audit of all Dnn.Platform instances to identify versions in use and prioritize patching accordingly. 4. Educate users about the risks of clicking on unsolicited or suspicious links, especially those that appear to come from internal or trusted sources. 5. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of XSS attacks. 6. Review and harden the configuration of SkinObjects and TokenReplace features to minimize exposure to untrusted input. 7. Monitor logs for unusual URL access patterns or repeated attempts to exploit URL parameters. 8. For organizations unable to immediately upgrade, consider disabling or restricting the use of TokenReplace in URLs or limiting the use of vulnerable SkinObjects as a temporary workaround.