GHSA-54mj-vcvj-q3v5 is a critical-severity (CVSS 10) Unrestricted File Upload vulnerability in Umbraco.Cms. O3 Security confirms whether GHSA-54mj-vcvj-q3v5 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Umbraco CMS has an arbitrary file upload vulnerability
Real-World Exposure
Umbraco.CmsReal-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
An arbitrary file upload vulnerability in Umbraco CMS v16.3.3 allows attackers to execute arbitrary code via uploading a crafted PDF file. While Umbraco provides hooks to perform file validation, it does not do implement filtering by default. Users are expected to implement their own validation.
Note: This vulnerability is disputed by Ubraco.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Umbraco.Cms | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Umbraco.Cms. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of Umbraco.Cms has shipped for GHSA-54mj-vcvj-q3v5 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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.
How O3 protects you
O3 pinpoints whether GHSA-54mj-vcvj-q3v5 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-54mj-vcvj-q3v5. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-54mj-vcvj-q3v5 in your dependencies?
O3 detects GHSA-54mj-vcvj-q3v5 across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.