CVE-2026-40306 DNN has same HostGUID for all new installs
Attackers can exploit identical Host GUIDs in new DNN installations to bypass security controls or impersonate hosts.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-40306?
CVE-2026-40306 is a medium-severity vulnerability in Dnnsoftware Dotnetnuke, published on 17 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-330
Which versions are affected by CVE-2026-40306?
2 open source packages ship an affected version, including DotNetNuke.Core. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
DotNetNuke.Core NuGet | From 10.0.0 | 10.2.2 |
DotNetNuke.Core NuGet | From 10.0.0 | 10.2.2 |
Products include Dnnsoftware Dotnetnuke.
How do I fix CVE-2026-40306?
Upgrade DotNetNuke.Core to 10.2.2 or later.
Is CVE-2026-40306 being exploited?
There is no known exploitation of CVE-2026-40306 in the wild and no public exploit code.
Other vulnerabilities in Dnnsoftware Dotnetnuke
- CVE-2017-9822 DotNetNuke (DNN) Remote Code Execution
- CVE-2018-15811 DotNetNuke (DNN) Inadequate Encryption Strength
- CVE-2018-18325 DotNetNuke (DNN) Inadequate Encryption Strength
- CVE-2025-64095 DNN Insufficient Access Control - Image Upload allows for Site Content Overwrite
- CVE-2006-3601 Privilege escalation in n/a
Sources
Also known as GHSA-2rhw-gw3f-477j.