CVE-2026-40306: DNN: Same HostGUID for all new installs

CVE-2026-40306 · Severity: medium · CVSS 6.5 · Published 2026-04-17

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.

Technologies: Dnnsoftware Dotnetnuke, DotNetNuke.Core (NuGet). Vendors: Dnnsoftware, NuGet.

Quick answers

Is CVE-2026-40306 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-40306 being exploited in the wild.
How severe is CVE-2026-40306?
Medium severity, with a CVSS score of 6.5, published 17 April 2026.
Which products and versions are affected?
DotNetNuke.Core (NuGet) >= 10.0.0, < 10.2.2, ECOSYSTEM:introduced=10.0.0,fixed=10.2.2.
Is there a fix for CVE-2026-40306?
Yes. DotNetNuke.Core (NuGet): upgrade to 10.2.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2026-40306?
Check whether you run Dnnsoftware Dotnetnuke or DotNetNuke.Core (NuGet) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • DotNetNuke.Core (NuGet): upgrade to 10.2.2 or later
    dotnet add package DotNetNuke.Core --version 10.2.2

Affected products

  • Dnnsoftware Dotnetnuke
  • DotNetNuke.Core (NuGet) >= 10.0.0, < 10.2.2, ECOSYSTEM:introduced=10.0.0,fixed=10.2.2

Identifiers

  • CVE-2026-40306
  • GHSA-2rhw-gw3f-477j

References

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