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.NET
.NET NuGet
Not in CISA KEV
HIGH severity

CVE-2026-40321 — DotNetNuke.Core

HIGH

CVE-2026-40321 is a high-severity (CVSS 8) CWE-87 vulnerability in DotNetNuke.Core. A fix is available for DotNetNuke.Core — see the affected versions and patch details below.

DotNetNuke.Core has stored cross-site-scripting (XSS) via SVG upload

Also known asGHSA-ffq7-898w-9jc4
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Nov 7, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • A successful exploit gives an attacker total control of the affected component, not partial access.
  • 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-2026-40321.

EPSS Exploitation Probability

via FIRST.org ↗
6.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs94th percentile — riskier than 94% of all scored CVEsHighest risk
0.00%3.29%6.58%9.87%0.0%6.4%May 26Sep 26Nov 26

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

How urgent is this, really

Where this sits among everything scored

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. 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.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
.NETNuGetDotNetNuke.Coreall versions10.2.2dotnet add package DotNetNuke.Core --version 10.2.2

Affected Products

1 product · 1 configurations
Application
dotnetnukednnsoftware
< 10.2.2
range

Detection & mitigation playbook

Open-source dependency

  1. 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.

  2. 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-2026-40321 is resolved across your whole dependency graph.

  3. 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.

Frequently Asked Questions

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.
O3 Security · Impact-Aware SCA

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CVE-2026-40321: DotNetNuke.Core — Fixed in 10.2.2