How severe is CVE-2026-40321?

CVE-2026-40321 has a CVSS 3.x base score of 8.0, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-40321 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 8% (94th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-40321?

CVE-2026-40321 affects Dnnsoftware Dotnetnuke. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-40321?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-40321 have an EU (EUVD) identifier?

Yes. CVE-2026-40321 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-24061.

When was CVE-2026-40321 published?

CVE-2026-40321 was published on 2026-04-17 and last updated on 2026-06-17.

CVE-2026-40321

CVE-2026-40321 is a high-severity vulnerability in Dnnsoftware Dotnetnuke with a CVSS 3.x base score of 8.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-87.

Key facts

Severity: High (CVSS 3.x base score 8.0)
EPSS exploit prediction: 8% (94th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-24061
Weakness: CWE-87
Affected product: Dnnsoftware Dotnetnuke
Published: 2026-04-17
Last modified: 2026-06-17

Description

DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. Prior to version 10.2.2, a user could upload a specially crafted SVG file that could include scripts that can target both authenticated and unauthenticated DNN users. The impact is increased if the scripts are run by a power user. Version 10.2.2 patches the issue.

Frequently asked questions

What is CVE-2026-40321?: DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. Prior to version 10.2.2, a user could upload a specially crafted SVG file that could include scripts that can target both authenticated and unauthenticated DNN users. The impact is increased if the scripts are run by a power user. Version 10.2.2 patches the issue.
How severe is CVE-2026-40321?: CVE-2026-40321 has a CVSS 3.x base score of 8.0, rated high severity. It is exploitable over network with high attack complexity, requires low privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-40321 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 8% (94th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-40321?: CVE-2026-40321 affects Dnnsoftware Dotnetnuke. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-40321?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-40321 have an EU (EUVD) identifier?: Yes. CVE-2026-40321 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-24061.
When was CVE-2026-40321 published?: CVE-2026-40321 was published on 2026-04-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:dnnsoftware:dotnetnuke:*:*:*:*:*:*:*:*

More vulnerabilities in Dnnsoftware Dotnetnuke

CVE-2025-64095 — Critical (CVSS 10.0): DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. Prior to…
CVE-2006-3601 — Critical (CVSS 10.0): ** UNVERIFIABLE ** Unspecified vulnerability in an unspecified DNN Modules module for DotNetNuke (.net nuke) allows…
CVE-2015-2794 — Critical (CVSS 9.8): The installation wizard in DotNetNuke (DNN) before 7.4.1 allows remote attackers to reinstall the application and gain…
CVE-2026-24838 — Critical (CVSS 9.1): DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. Prior to…
CVE-2025-59545 — Critical (CVSS 9.0): DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. Prior to…
CVE-2020-5187 — High (CVSS 8.8): DNN (formerly DotNetNuke) through 9.4.4 allows Path Traversal (issue 2 of 2).

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