CVE-2026-110194

OAuth registration could make the MCP gateway contact an unintended service

IBM · ContextForge MCP Gateway OAuth registration

First documented disclosure · Review checkpoint

Summary

Dynamic client registration allowed outbound requests to destinations outside the intended trust boundary. The gateway could reach services accessible from its network and expose information about that network.

Severity and exploitation evidence

Medium · 5.4/10 · CVSS 3.1. Severity source.

Exploitation not established: The reviewed advisory does not report malicious exploitation.

Exploitation evidence source

Technical severity is not a measure of observed attacks or of risk to your deployment. Attempts, demonstrations, and successful compromise retain the qualifications in the source.

How the weakness works

Dynamic client registration allowed outbound requests to destinations outside the intended trust boundary.

Conditions required

An authenticated caller could use the affected gateway configuration.

Potential impact

The gateway could reach services accessible from its network and expose information about that network.

Affected versions and configurations

1.0.0 through 1.0.11.

Fix and mitigation status

1.1.0.

Practical next steps

Upgrade, or disable dynamic client registration or restrict it to trusted issuers and limit who can create gateways.

Operating lesson

Authorize OAuth discovery destinations before the gateway contacts them.

Evidence and limits

The public fix discussion described this issue on 2026-09-22. The formal advisory followed on 2026-11-13, and the CVE record on 2026-11-13.

Sources