CVE-2026-40306: DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem

Routine

MEDIUM 6.5REMOTEWATCHLISTUPGRADE

CVE-2026-40306 is a medium-severity flaw (CVSS 6.5) affecting dotnetnuke. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	6.5 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.2% (top 93%)
CISA exploited list	No
Weakness	CWE-330
Published	2026-04-17
Last modified	2026-10-26

Publisher (CNA): GitHub, Inc. · Vendor: dnnsoftware

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-17 22:16 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

dnnsoftware dotnetnuke UPGRADE

Affected: >= 10.0.0 and < 10.2.2

Fixed in: 10.2.2

Safe to downgrade to: a release before 10.0.0

1. Check installed version

apt-cache policy dotnetnuke || rpm -q dotnetnuke || dotnetnuke --version

2. UPGRADE to 10.2.2 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade dotnetnuke

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade dotnetnuke

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 10.0.0 (Debian / Ubuntu)

apt-cache madison dotnetnuke sudo apt install dotnetnuke=<VERSION_BEFORE_10.0.0> sudo apt-mark hold dotnetnuke

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list dotnetnuke sudo dnf downgrade dotnetnuke-<VERSION_BEFORE_10.0.0> sudo dnf versionlock add dotnetnuke

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-40306?

dotnetnuke: upgrade to 10.2.2. Exact commands for each OS are on this page.

Is CVE-2026-40306 being exploited?

CVE-2026-40306 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-40306 affect?

CVE-2026-40306 affects dotnetnuke. Severity is medium (CVSS 6.5). 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 pat

How urgent is CVE-2026-40306?

Priority 34/100. Remotely exploitable, no login, no user action; On your watchlist

Related CVEs

CVE-2026-40321 HIGH 8.0 UPGRADE DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem
CVE-2026-40305 MEDIUM 4.3 UPGRADE DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem

References

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