CVE-2026-24837 is a cross-site scripting (XSS) vulnerability classified under CWE-79 affecting the Dnn.Platform, an open-source web content management system widely used within the Microsoft ecosystem. The vulnerability exists in versions starting from 9.0.0 up to but excluding 9.13.10 and 10.2.0. It stems from improper neutralization of input during web page generation, specifically in the handling of module friendly names within the Persona Bar interface. Malicious actors can inject scripts into the module friendly name field, which are then executed during certain module operations. This execution context allows attackers to perform actions such as session hijacking, privilege escalation, or injecting further malicious payloads. The CVSS 3.1 score of 7.7 reflects a high severity, with attack vector being network-based but requiring high privileges and user interaction. The vulnerability’s scope is classified as changed, indicating that exploitation can affect resources beyond the initially vulnerable component. Although no exploits have been reported in the wild, the presence of this vulnerability in a widely deployed CMS platform poses a significant risk, especially in environments where users have elevated privileges. The issue was addressed in versions 9.13.10 and 10.2.0 by properly sanitizing input to prevent script injection.

For European organizations, the impact of CVE-2026-24837 can be substantial. Given that Dnn.Platform is used in various sectors including government, education, and enterprises relying on Microsoft technologies, exploitation could lead to unauthorized access to sensitive data, defacement of websites, or disruption of services. The XSS vulnerability allows attackers to execute arbitrary scripts in the context of authenticated users with high privileges, potentially enabling lateral movement within networks or theft of credentials. This can compromise confidentiality, integrity, and availability of critical systems. The requirement for high privileges and user interaction somewhat limits the attack surface but does not eliminate risk, especially in environments with many privileged users or where social engineering is feasible. The vulnerability could also be leveraged as a stepping stone for more complex attacks targeting European infrastructure or data. Organizations failing to patch may face regulatory repercussions under GDPR if personal data is exposed or manipulated.

European organizations should immediately assess their Dnn.Platform versions and upgrade to 9.13.10 or 10.2.0 or later to remediate this vulnerability. In the interim, restrict access to the Persona Bar and module management interfaces to only trusted administrators and monitor for unusual activity. Implement Content Security Policy (CSP) headers to reduce the impact of potential XSS exploitation. Conduct regular security training to reduce the risk of social engineering that could facilitate exploitation. Employ web application firewalls (WAFs) with rules tuned to detect and block suspicious script injections targeting module friendly names. Review and harden user privilege assignments to minimize the number of users with high-level access. Finally, perform routine security audits and penetration testing focusing on CMS components to detect similar injection flaws.