CVE-2025-59535

Arbitrary themes can be loaded through query parameters. If an installed theme had a vulnerability, even if it was not used on any page, this could be loaded on unsuspecting clients without knowledge of the site owner.

Details

Many people who run DNN sites have a number of installed themes that they do not actually use. This could be because they were testing many themes during initial setup, because they have changed themes over time, or because they have development and production versions of a theme. Whatever the reason, many times the unused themes will become outdated over time as site admins wouldn't have reason to update something that is not used. However, this could introduce an entry point to exploit a vulnerable theme by making the server run the unused theme for unsuspecting client requests. Depending on the vulnerability in a theme, this could lead to server side or client side arbitrary code execution. With DNN 10.1.0 this functionality is now disabled by default but a setting was introduced in the Security module to turn activate the functionality.

The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths. Typical impact: varies by context: data corruption, logic bypass, or denial of service.

CVE-2025-59535 has a CVSS score of 6.5 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (10.1.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2025-59535? CVE-2025-59535 is a medium-severity improper input validation vulnerability in DotNetNuke.Core (nuget), affecting versions < 10.1.0. It is fixed in 10.1.0. The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths.
2. How severe is CVE-2025-59535? CVE-2025-59535 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of DotNetNuke.Core are affected by CVE-2025-59535? DotNetNuke.Core (nuget) versions < 10.1.0 is affected.
4. Is there a fix for CVE-2025-59535? Yes. CVE-2025-59535 is fixed in 10.1.0. Upgrade to this version or later.
5. Is CVE-2025-59535 exploitable, and should I be worried? Whether CVE-2025-59535 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2025-59535 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2025-59535? Upgrade DotNetNuke.Core to 10.1.0 or later.