CVE-2026-40321

Q: How do I fix CVE-2026-40321?

Upgrade dotnetnuke to 10.2.2 or later.

Q: Is CVE-2026-40321 being actively exploited?

Not that we know of. CVE-2026-40321 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 7.6% is the estimated probability that it will be exploited in the next 30 days. That is higher than 94% of all scored CVEs.

Q: How severe is CVE-2026-40321?

CVE-2026-40321 has a CVSS v3 base score of 8.0, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

Q: What does CVE-2026-40321 affect?

Published advisories record a fix for dotnetnuke (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

HIGHEPSS 94th pctl

8.0

CVSS v3

NVD

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.

CWE-87

How to fix

Remediation Available

dotnetnukeNVD

Affected:< 10.2.2Fixed in:10.2.2CVE-2026-40321derived from NVD

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredLow

User InteractionRequired

ScopeChanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H

Exploit Intelligence

7.60%probability of exploitation in 30 days

94thpercentile

High risk: more likely to be exploited than 94% of all known CVEs.

References

Vendor Advisory1

github.com

Release Notes1

github.com

Related Vulnerabilities

Other CWE-87 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2023-35161	Critical	9.6	2.4%	-	Fix
CVE-2023-35160	Critical	9.6	2.3%	-	Fix
CVE-2023-35159	Critical	9.6	2.2%	-	Fix
CVE-2023-35156	Critical	9.6	2.1%	-	Fix
CVE-2023-35158	Critical	9.6	2.0%	-	Fix
CVE-2022-36033	Medium	6.1	1.2%	-	Fix

Common questions

How do I fix CVE-2026-40321?

Upgrade dotnetnuke to 10.2.2 or later.

Is CVE-2026-40321 being actively exploited?

Not that we know of. CVE-2026-40321 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 7.6% is the estimated probability that it will be exploited in the next 30 days. That is higher than 94% of all scored CVEs.

How severe is CVE-2026-40321?

CVE-2026-40321 has a CVSS v3 base score of 8.0, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-40321 affect?

Published advisories record a fix for dotnetnuke (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

Embed a live status badge for CVE-2026-40321

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-24.