# CVE-2026-50194: Steeltoe vulnerable to management-port isolation bypass via spoofed Host header

> Attackers can bypass management endpoint port isolation by spoofing the Host header, exposing sensitive actuator endpoints in Steeltoe cloud-native applications.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Jun 2026
- **Updated:** 18 Jun 2026
- **Also known as:** GHSA-58f6-6rj2-3v8r

## What is CVE-2026-50194?

CVE-2026-50194 is a high-severity vulnerability in SteeltoeOSS Steeltoe.Management.Endpoint, published on 17 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key), CWE-288 (Authentication Bypass Using an Alternate Path or Channel)

## Which versions are affected by CVE-2026-50194?

4 open source packages ship an affected version, including Steeltoe.Management.Endpoint and Steeltoe.Management.EndpointCore.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `Steeltoe.Management.Endpoint` | NuGet | All versions | 4.2.0 |
| `Steeltoe.Management.Endpoint` | NuGet | All versions | 4.2.0 |
| `Steeltoe.Management.EndpointCore` | NuGet | From 3.2.2 | 3.4.0 |
| `Steeltoe.Management.EndpointCore` | NuGet | From 3.2.2 | 3.4.0 |

## How do I fix CVE-2026-50194?

Upgrade Steeltoe.Management.Endpoint to 4.2.0 or later.

## Is CVE-2026-50194 being exploited?

There is no known exploitation of CVE-2026-50194 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-50194 and fix it if it is affected.

What it is: CVE-2026-50194 is a high-severity vulnerability in SteeltoeOSS Steeltoe.Management.Endpoint, published on 17 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-50194 in the wild and no public exploit code.

Affected packages and fixed versions:
- Steeltoe.Management.Endpoint (NuGet): affected all versions; fixed in 4.2.0
- Steeltoe.Management.Endpoint (NuGet): affected all versions; fixed in 4.2.0
- Steeltoe.Management.EndpointCore (NuGet): affected from 3.2.2; fixed in 3.4.0
- Steeltoe.Management.EndpointCore (NuGet): affected from 3.2.2; fixed in 3.4.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-50194/ (Markdown: https://insights.sbomify.com/CVE-2026-50194/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-50194
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-50194
- OSV: https://osv.dev/vulnerability/CVE-2026-50194

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-50194/
Summaries are generated and may contain mistakes; the official description above is the record.