CVE-2025-59539: 
C# vulnerability analysis and mitigation

CVE-2025-59539 is a Stored Cross-Site Scripting (XSS) vulnerability discovered in DotNetNuke.Core's Profile Biography field. The vulnerability was published on September 22, 2025, affecting all versions of DotNetNuke.Core below 10.1.0 (GitHub Advisory).

The vulnerability allows users to inject JavaScript code into their profile biography field using special syntax, bypassing existing sanitization measures. The vulnerability has been assigned a CVSS v3.1 base score of 6.3 (Moderate) with the vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L, indicating network attack vector, low attack complexity, low privileges required, and no user interaction needed (GitHub Advisory).

When exploited, the injected JavaScript code executes in the context of the website for any user viewing the profile, including administrators and superusers. This can lead to unauthorized access to user data, potential session hijacking, and other malicious activities typically associated with XSS attacks (GitHub Advisory).

The vulnerability has been patched in DotNetNuke.Core version 10.1.0. Organizations using affected versions should upgrade to version 10.1.0 or later to mitigate this security risk (GitHub Advisory).