CVE-2026-112136

Studio Pro could expose its local MCP service to the network

Siemens / Mendix · Mendix Studio Pro MCP server

First documented disclosure · Review checkpoint

Summary

The MCP server could accept requests from systems outside the developer’s computer.

Severity and exploitation evidence

Critical · 9.2/10 · CVSS 4.0. Severity source.

Exploitation not established: The reviewed sources describe the vulnerability and its conditions. They do not identify 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

The HTTP listener did not reliably bind only to the loopback interface.

Conditions required

Studio Pro’s MCP server must be running and reachable through the host firewall. Siemens notes that standard Windows firewall policies normally block external access.

Potential impact

A remote caller could perform operations available through the developer’s MCP service. Siemens rates the potential impact to confidentiality, integrity and availability high.

Affected versions and configurations

Studio Pro 11.15.0 up to 11.16.0, exclusive, and the 11.12 line from 11.12.6 up to 11.12.7, exclusive.

Fix and mitigation status

11.16.0 or 11.12.7 on the corresponding release line.

Practical next steps

Install the fix for the Studio Pro release line. Until then, block inbound network access to the MCP listener and use an authenticated channel if remote access is essential.

Operating lesson

Verify the network interfaces used by tools designed for local development.

Evidence and limits

Siemens publishes CVSS 4.0 at 9.2 and CVSS 3.1 at 8.8. Network reachability depends on the host configuration.

Sources