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High nvd · CVE-2026-59176

CVE-2026-59176: Functype is a family of TypeScript functional programming libraries. Prior to 1.4.4, the `set_functype_version` MCP tool

Published Oct 28, 2026 CVSS 7.8

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 without authentication in stdio mode. A connected AI assistant susceptible to indirect prompt injection can also be induced to invoke it from a malicious document or web page. In non-default TRANSPORT_TYPE=httpStream deployments, a network-accessible attacker does not require local access. Successful execution can read process secrets, modify files, or terminate the server. This issue is fixed in version 1.4.4.

Affected AI Products

prompt injection indirect prompt mcp server
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