v1.5.7

Release v1.5.7

Release type: stable
Release line: 1.5.x
Branch: release/1.5.x

Installation

npm install @frontmcp/sdk@1.5.7

Security

This release fixes two reported vulnerabilities:

• GHSA-mp29-fxh8-92px (critical) — CodeCall sandbox escape to host RCE via a live schema object exposed by getTool.
• GHSA-h8wf-g76c-wjwg (high) — frontmcp install could write outside ~/.frontmcp via manifest path traversal.

Thank you to @fg0x0 for responsibly reporting both issues. The reports were precise and included working reproductions, which made them quick to confirm and fix — we appreciate it.

What's New

CHANGELOG

Features

• Introduced toSandboxValue function to ensure values crossing the sandbox boundary are structured-cloneable, enhancing security and reliability when handling complex data types.
• Added CodeCallToolDescription interface to provide a standardized way of describing tools in sandboxed scripts, improving tool introspection capabilities.

Improvements

• Enhanced the copyIfExists function to use asynchronous operations, resulting in improved performance and reliability during file operations.
• Updated getTool function to utilize toPlainJson, ensuring that tool descriptions are safely projected into JSON, which enhances compatibility and reduces errors.
• Improved error handling in resolveContainedFile and copyIfExists functions to better manage invalid paths and non-cloneable values, increasing robustness.

Breaking Changes

• The getTool function now returns a CodeCallToolDescription object instead of a raw schema, which may require updates to existing codebases that rely on the previous structure.

What's Changed

• feat: enhance sandbox boundary checks to prevent access to internal constructors and ensure plain JSON serialization of tool schemas by @frontegg-david in #512

Full Changelog: v1.5.6...v1.5.7