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.NET
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Not in CISA KEV
MEDIUM severity

CVE-2020-9472 — UmbracoCms

MEDIUM

CVE-2020-9472 is a medium-severity (CVSS 6.5) Unrestricted File Upload vulnerability in UmbracoCms. 3 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for UmbracoCms — see the affected versions and patch details below.

Unrestricted Upload of File with Dangerous Type in Umbraco CMS

Also known asGHSA-j66f-h9hm-975m
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
3 known
Exploitation data as of Nov 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
2.1%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs82th percentile — riskier than 82% of all scored CVEsHighest risk
1.61%1.96%2.31%2.66%2.2%2.1%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
.NETUmbracoCms

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

Umbraco CMS 8.5.3 allows an authenticated file upload (and consequently Remote Code Execution) via the Install Package functionality.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
.NETNuGetUmbracoCmsall versions8.5.4dotnet add package UmbracoCms --version 8.5.4

Affected Products

1 product · 1 configurations
Application
umbraco cmsumbraco
1 version
8.5.3
Exploits & PoCs
3

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Umbraco CMS 8.5.3 allows an authenticated file upload (and consequently …

gitlab.comNVDMar 2020

Report on gitlab.com

gitlab.comAwesomePocJun 2020

Detection & mitigation playbook

Open-source dependency

  1. Detect

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

  2. Fix

    Update UmbracoCms to 8.5.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-9472 is resolved across your whole dependency graph.

  3. Workarounds

    Treat uploaded files as untrusted until proven otherwise: validate the actual content type rather than the supplied extension, store uploads outside the web root on a volume mounted without execute permission, and rename them to server-generated identifiers so an attacker cannot choose the path a request will later resolve.

Frequently Asked Questions

Umbraco CMS 8.5.3 allows an authenticated file upload (and consequently Remote Code Execution) via the Install Package functionality.
O3 Security · Impact-Aware SCA

Is CVE-2020-9472 in your dependencies?

Find it across NuGet, including transitive dependencies.

Scan my dependencies How O3 SCA works
CVE-2020-9472: UmbracoCms RCE — Fixed in 8.5.4