Functype is a family of TypeScript functional programming libraries. Prior to 1.4.4, the set_functype_version MCP tool in functype-mcp-server accepts an unconstrained version string using only z.string() validation in packages/mcp-server/src/index.ts and interpolates it into functype@ for pnpm add. Package-alias syntaxes such as file:, npm:, URLs, or paths can cause an arbitrary local or remote package to be installed as functype. Immediately afterward, initDocsData(true) in packages/mcp-server/src/lib/docs/data.ts resolves functype/cli and dynamically imports the newly installed module, executing attacker-controlled JavaScript with the MCP server process's privileges. Any MCP client able to send a tools/call request invoking the tool can exploit the flaw; the tool is enabled by default…