How severe is CVE-2026-40306?

No CVSS score has been assigned to CVE-2026-40306 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-40306?

CVE-2026-40306 affects the following packages: DotNetNuke.Core (NuGet). Ecosystems affected: NuGet.

How do I fix CVE-2026-40306?

Update DotNetNuke.Core to 10.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-40306 is resolved across your whole dependency graph.

How do I detect CVE-2026-40306 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for DotNetNuke.Core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-40306 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2026-40306 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-40306 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-40306?

CVE-2026-40306 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 7th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-40306?

CVE-2026-40306 is classified as Insufficient Random Values (CWE-330). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-40306 published, and has it been updated?

CVE-2026-40306 was published on April 17, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

.NET NuGet

Not in CISA KEV

CVE-2026-40306 — DotNetNuke.Core

CVE-2026-40306 is a Insufficient Random Values vulnerability in DotNetNuke.Core. A fix is available for DotNetNuke.Core — see the affected versions and patch details below.

DNN has same HostGUID for all new installs

Also known asGHSA-2rhw-gw3f-477j

Published

Apr 17, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 9, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-40306.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs7th percentile — riskier than 7% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

.NETDotNetNuke.Core

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.

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 Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`DotNetNuke.Core`	≥ 10.0.0&&< 10.2.2	10.2.2`dotnet add package DotNetNuke.Core --version 10.2.2`

Affected Products

1 product · 1 configurations

Application

dotnetnukednnsoftware

≥ 10.0.0 && < 10.2.2

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for DotNetNuke.Core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update DotNetNuke.Core to 10.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-40306 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.