CVE-2026-50194
Steeltoe vulnerable to management-port isolation bypass via spoofed Host header
Description
### Summary When Steeltoe management endpoints 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. ### Impact An unauthenticated remote attacker can reach every actuator endpoint using a specially crafted HTTP request. ### Affected configuration - The application's public port is accessible over from the network. - `Management:Endpoints:Port` is configured to a value different from the application's main listener port. - The request scheme matches `Management:Endpoints:SslEnabled`. For example, `http` when `SslEnabled` is `false` (the default), or `https` when `SslEnabled` is `true`. ### Mitigations 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. - Configure the reverse proxy or load balancer to enforce the `Host` header value and prevent clients from setting an arbitrary port.
How to fix CVE-2026-50194
To remediate CVE-2026-50194, upgrade the affected package to a fixed version below.
- —upgrade to 4.2.0 or later
- —upgrade to 3.4.0 or later
Is CVE-2026-50194 being exploited?
No exploitation signal available. Neither CISA KEV nor a current EPSS score has been published for CVE-2026-50194.
Affected packages (2)
- from 0, < 4.2.0
- >= 3.2.2, < 3.4.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N |