Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
.NET
.NET NuGet
Not in CISA KEV
MEDIUM severity

GHSA-936x-wgqv-hhgq — UmbracoCms

MEDIUM

GHSA-936x-wgqv-hhgq is a medium-severity (CVSS 6.5) Path Traversal vulnerability in UmbracoCms. 3 public exploit references exist, so weaponization risk is real. A fix is available for UmbracoCms — see the affected versions and patch details below.

Authenticated path traversal in Umbraco CMS

Also known asCVE-2020-5811
Published
Apr 13, 2021
Updated
Sep 10, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
3 known
Exploitation data as of Sep 24, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
9.5%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs95th percentile — riskier than 95% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

GHSA-936x-wgqv-hhgq plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

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

An authenticated path traversal vulnerability exists during package installation in Umbraco CMS <= 8.9.1 or current, which could result in arbitrary files being written outside of the site home and expected paths when installing an Umbraco package.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
.NETNuGetUmbracoCmsall versions8.9.2dotnet add package UmbracoCms --version 8.9.2
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.

EDB-50241webappsaspx

Umbraco CMS 8.9.1 - Directory Traversal

by BitTheByte · Aug 31, 2021

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 8.9.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-936x-wgqv-hhgq 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.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-936x-wgqv-hhgq can be triaged on real exposure rather than presence alone.

Tailored to GHSA-936x-wgqv-hhgq. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

An authenticated path traversal vulnerability exists during package installation in Umbraco CMS <= 8.9.1 or current, which could result in arbitrary files being written outside of the site home and expected paths when installing an Umbraco package.
O3 Security · Impact-Aware SCA

Is GHSA-936x-wgqv-hhgq in your dependencies?

O3 Security finds GHSA-936x-wgqv-hhgq across NuGet dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-936x-wgqv-hhgq: Medium 6.5 severity | O3 Security