CVE-2026-50194 is a high-severity (CVSS 8.2) CWE-288 vulnerability in Steeltoe.Management.Endpoint. O3 Security confirms whether CVE-2026-50194 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Steeltoe vulnerable to management-port isolation bypass via spoofed Host header
Real-World Exposure
Steeltoe.Management.Endpoint.NETSteeltoe.Management.EndpointCoreReal-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
Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. When Steeltoe management endpoints versions 3.2.2 through 3.3.0 and 4.1.0 are configured to listen on an alternate port (Management:Endpoints:Port is configured), the middleware responsible for restricting access to the endpoints uses the Host HTTP header rather than the actual network socket port. Versions 3.4.0 and 4.2.0 patch the issue. If an immediate upgrade to a patched version is not possible, add explicit ASP.NET Core authorization (RequireAuthorization) to all sensitive actuator endpoints as a defense-in-depth measure independent of port isolation and/or configure the reverse proxy or load balancer to enforce the Host header value and prevent clients from setting an arbitrary port.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Steeltoe.Management.Endpoint | all versions | 4.2.0 |
| .NETNuGet | Steeltoe.Management.EndpointCore | ≥ 3.2.2&&< 3.4.0 | 3.4.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Steeltoe.Management.Endpoint. 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.
Fix
Update Steeltoe.Management.Endpoint to 4.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-50194 is resolved across your whole dependency graph.
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.
How O3 protects you
O3 pinpoints whether CVE-2026-50194 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 CVE-2026-50194. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-50194 in your dependencies?
O3 detects CVE-2026-50194 across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.