Please do not report security vulnerabilities through public GitHub issues.
Instead, email security@coplay.dev with:
- A clear description of the issue
- Steps to reproduce or a proof-of-concept
- The version of MCP for Unity affected (UPM package + Python server)
- Your OS, Unity Editor version, and MCP client
- Optional: a suggested fix
We aim to acknowledge reports within 3 business days and to share an initial assessment within 10 business days. Critical fixes are released as patch versions on both main and the beta channel.
| Version | Supported |
|---|---|
latest (main) |
Yes |
latest beta (beta) |
Yes |
| older releases | No — please upgrade |
MCP for Unity is intentionally fail-closed:
- HTTP Local binds to loopback only by default (
127.0.0.1,localhost,::1). LAN bind (0.0.0.0,::) requires explicit opt-in via Allow LAN Bind (HTTP Local) in Advanced Settings. - HTTP Remote requires
https://by default. Plaintexthttp://for remote endpoints requires explicit opt-in via Allow Insecure Remote HTTP. - Remote-hosted mode requires API key authentication. See Remote Server Auth.
If you find a way to bypass any of these guards, that qualifies as a security vulnerability and warrants a private report.
- Remote code execution via crafted MCP messages
- Auth bypass on remote-hosted server
- Filesystem read/write outside the intended Unity project root
- Network requests that escape the configured allow-list
- Credential or API-key leakage in logs, telemetry, or error responses
- Tool actions that intentionally modify the Unity project (that's the product)
- Issues that require an attacker to already have shell access to the host
- Vulnerabilities in third-party dependencies — please report those upstream first; we'll bump our pins after the upstream fix lands
Once a fix is shipped, we publish a security advisory on the GitHub Security tab and credit the reporter (unless they prefer anonymity).