CVE-2025-59535: DotNetNuke.Core allows loading of unused themes on anonymous clients through query parameters
Summary 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 Whatever the reason, many times the unused themes will become outdated over time as site admins wouldn't have reason to update something that is not used.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.
Other sources
DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. Prior to version 10.1.0, 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. This issue has been patched in version 10.1.0.
— MITRE
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2025-59535?
CVE-2025-59535 is considered a high-severity vulnerability due to its potential to allow arbitrary themes to be loaded.
How do I fix CVE-2025-59535?
To mitigate CVE-2025-59535, upgrade to DNN version 10.1.0 or later, which addresses the vulnerability.
What products are affected by CVE-2025-59535?
CVE-2025-59535 affects DNN and DNN DotNetNuke.Core versions before 10.1.0.
What type of vulnerability is CVE-2025-59535?
CVE-2025-59535 is classified as a security vulnerability that allows arbitrary theme loading through query parameters.
Can CVE-2025-59535 be exploited without using the vulnerable theme?
Yes, CVE-2025-59535 can be exploited if a vulnerable theme is installed, regardless of whether it is actively used on any page.