CVE-2026-24833 is a cross-site scripting (XSS) vulnerability classified under CWE-79 found in the Dnn.Platform, an open-source web content management system widely used in the Microsoft ecosystem. The vulnerability arises from improper neutralization of input during web page generation, specifically in the richtext description field of modules installed on the platform. Prior to versions 9.13.10 and between 10.0.0 and 10.2.0, this description field could contain malicious scripts that execute within the Persona Bar, a management interface for administrators and content managers. The attack vector requires an authenticated user with high privileges to install or modify a module with malicious content, and user interaction is necessary to trigger the script execution. The vulnerability affects confidentiality, integrity, and availability by allowing attackers to execute arbitrary scripts, potentially leading to session hijacking, privilege escalation, or persistent code execution within the administrative interface. The scope is broad as it affects all installations running the vulnerable versions of Dnn.Platform. Although no known exploits have been reported in the wild, the vulnerability's presence in a critical administrative interface makes it a significant risk. The issue was addressed in versions 9.13.10 and 10.2.0 by properly sanitizing input in the module description field to prevent script execution.

For European organizations, this vulnerability poses a substantial risk, especially for those relying on Dnn.Platform for web content management in critical infrastructure, government, or enterprise environments. Successful exploitation can lead to unauthorized access to administrative functions, data leakage, and potential disruption of web services. The ability to execute scripts in the Persona Bar could allow attackers to manipulate site content, steal credentials, or deploy further attacks within the network. Given the high CVSS score (7.7) and the requirement for privileged access, the impact is particularly severe in environments with multiple administrators or where access controls are insufficiently strict. The vulnerability could also undermine trust in public-facing websites and portals, affecting reputation and compliance with data protection regulations such as GDPR. Additionally, the cross-site scripting nature of the flaw could facilitate phishing or social engineering attacks targeting users of the platform.

European organizations should immediately upgrade all affected Dnn.Platform installations to versions 9.13.10 or 10.2.0 or later, where the vulnerability is patched. Beyond patching, organizations should enforce strict role-based access controls to limit module installation and modification privileges to trusted administrators only. Implementing comprehensive input validation and output encoding on all user-supplied content fields, especially richtext inputs, will reduce the risk of similar vulnerabilities. Deploying Content Security Policy (CSP) headers can help mitigate the impact of potential XSS attacks by restricting script execution sources. Regular security audits and penetration testing focused on the Persona Bar and module management interfaces are recommended to detect any residual or new vulnerabilities. Monitoring logs for unusual module installation or modification activities can provide early detection of exploitation attempts. Finally, educating administrators about the risks of installing untrusted modules and the importance of applying security updates promptly is essential.