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nwiizo/tfmcp

v0.2.1 Security

This release includes 2 security fixes for security teams reviewing exposed deployments.

Published 21h MCP Developer Tools
✓ No known CVEs patched
Read the diff → Tool health → What is this tool? →
This release patches 2 known CVEs

Topics

mcp mcp-server terraform

Affected surfaces

auth breaking_upgrade

Summary

AI summary

Removed request‑scoped TFE_TOKEN, Authorization, and TFE_ADDRESS passthrough to prevent confused‑deputy attacks.

Full changelog

Changelog

All notable changes to tfmcp are documented in this file.

0.2.1 - 2026-07-26

v0.2.1 consolidates the completed v0.2.x work into one stable release while
preserving tfmcp's local-first Terraform workflows.

Added

  • Public and private Terraform Registry tools, including the
    registry-private toolset and HashiCorp-compatible provider, module, and
    policy aliases.
  • Local project inspection, Terraform entrypoint detection, plan review,
    provider lockfile checks, module health analysis, and state safety checks.
  • HCP Terraform and Terraform Enterprise read APIs for organizations,
    projects, workspaces, runs, plans, applies, variables, policy sets, variable
    sets, tags, stacks, and private Registry content.
  • Explicitly gated HCP/TFE operations, including
    attach_variable_set_to_workspaces; operations remain disabled until
    ENABLE_TF_OPERATIONS=true.
  • Streamable HTTP transport with loopback defaults, health and metrics
    endpoints, stateful/stateless sessions, Host and Origin validation, rate
    limits, TLS file wiring, organization allowlists, and heartbeat control.
  • MCP resources including
    /terraform/providers/{namespace}/name/{name}/version/{version}.

Changed

  • Updated the tested and containerized Terraform baseline to 1.15.8.
  • Updated the declared RMCP SDK baseline to 1.8.
  • Set and continuously test the Rust 1.88 MSRV; Docker builds use the same
    locked dependency graph instead of an unpinned nightly toolchain.
  • Split MCP protocol/analysis concerns and TFE client operations, configuration,
    encoding, and response handling into narrower modules.
  • Consolidated Terraform formatting and refresh wrappers around explicit mode
    enums to remove duplicated control flow.
  • Added cargo coupling and similarity-rs architecture gates to CI and the
    release process.

Security

  • Streamable HTTP validates request origins in every CORS mode and uses
    loopback-only origins by default.
  • Removed request-scoped TFE_TOKEN, Authorization, and TFE_ADDRESS
    passthrough. Downstream HCP/TFE calls use only server-configured credentials,
    preventing confused-deputy and token-passthrough behavior.
  • HCP/TFE writes, local dangerous operations, and auto-approve remain separate,
    fail-closed gates.
  • Organization allowlists reject account-wide and ID-scoped requests whose
    ownership cannot be verified.
  • TFE response bodies, HTTP metric routes, and rate-limit session state are
    bounded; sensitive credentials are not returned by status APIs.

HashiCorp v1.0.x Compatibility

The compatible surface includes get_plan_json_output, get_apply_logs,
list_variable_sets, attach_variable_set_to_workspaces,
read_workspace_tags, and list_stacks. tfmcp also retains capabilities
beyond API mirroring: local Terraform CLI workflows, entrypoint detection,
module health analysis, state safety checks, and local dangerous-operation gates.

Breaking Changes

  • Removed request-scoped `TFE_TOKEN`, `Authorization`, and `TFE_ADDRESS` passthrough; downstream HCP/TFE calls now use only server‑configured credentials.

Security Fixes

  • Streamable HTTP transport now validates request origins in every CORS mode and defaults to loopback‑only origins.
  • Removed request‑scoped `TFE_TOKEN`, `Authorization`, and `TFE_ADDRESS` passthrough, preventing confused‑deputy and token‑passthrough behavior.

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About nwiizo/tfmcp

Terraform Model Context Protocol (MCP) Tool - An experimental CLI tool that enables AI assistants to manage and operate Terraform environments. Supports reading Terraform configurations, analyzing plans, applying configurations, and managing state with Claude Desktop integration. ⚡

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Beta — feedback welcome: [email protected]