If you find a security issue in Monolith, please report it privately first:

• Preferred: Open a GitHub Security Advisory
• Alternative: Email leviathansteam666@gmail.com with [Monolith Security] in the subject

I aim to acknowledge reports within 7 days and ship a fix or mitigation in the next release. Please do not open a public GitHub issue for security-impacting findings before that window.

Monolith is a developer tool. The MCP HTTP server runs locally inside the Unreal Editor and is intended for use by AI coding assistants on the same machine. It is not designed to be exposed to untrusted networks or browsers.

In scope:

• Cross-origin browser exploitation against localhost:9316
• Auto-update supply-chain integrity
• Any code path where attacker-controlled input from a remote source reaches the editor

Out of scope (assumed compromised — Monolith is the least of your worries):

• Local malware running on the developer's machine
• A compromised maintainer GitHub account pushing a malicious release — partially mitigated by SHA256 verification once the marker is present in release notes
• Denial of service on the local MCP server — it's a developer tool, restart the editor

Only the latest tagged release is supported. Older versions do not receive backports.

• Keep bAutoUpdateEnabled = false (the default as of v0.14.6) and apply updates manually
• Verify the Monolith-SHA256: value in the release notes against the SHA256 of the downloaded zip before extracting (auto-updater does this for you when enabled)
• Do not run the editor on a machine where untrusted users have local accounts
• The MCP server binds to all network interfaces (limitation of UE's FHttpServerModule). If your machine is on an untrusted LAN, either:
  • Add a Windows Firewall rule blocking inbound TCP on port 9316 from non-loopback addresses, OR
  • Set bMcpServerEnabled = false in Editor Preferences > Plugins > Monolith when not actively using AI tooling

Thanks to security researchers who have responsibly disclosed issues:

• @krojew — CORS wildcard, auto-update integrity (Issue #38, 2026-04)