CVE-2026-40306: DNN has same HostGUID for all new installs

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-17 · updated 2026-10-26
Weakness: CWE-330

Description

DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. All new installations of DNN 10.x.x - 10.2.1 have the same Host GUID. This does not affect upgrades from 9.x.x. Version 10.2.2 patches the issue.

Affected products

DotNetNuke CMS Fixed in 9.1.1: from 10.0.0 before 10.2.2 — fixed in 10.2.2

How to fix

Upgrade to a fixed version: DotNetNuke CMS Fixed in 9.1.1 10.2.2. Check the vendor advisory for mitigations.

References

https://github.com/dnnsoftware/Dnn.Platform/releases/tag/v10.2.2
https://github.com/dnnsoftware/Dnn.Platform/security/advisories/GHSA-2rhw-gw3f-477j

Get alerted when CVE-2026-40306 or the next vulnerability affects your stack