CVE Catalog

CVE-2026-59176

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.21%

11th percentile - higher than 11% of all known CVEs

Summary

In functype-mcp-server prior to 1.4.4, the set_functype_version MCP tool accepts an unconstrained version string and interpolates it into functype@<version> for pnpm add, allowing an arbitrary local or remote package to be installed as functype. initDocsData(true) then dynamically imports the newly installed module, executing attacker-controlled JavaScript with the MCP server process's privileges.

Risk Assessment

Any MCP client able to send a tools/call request can exploit the flaw, and in httpStream mode a remote attacker can too. Successful execution can read process secrets, modify files, or terminate the server.

Recommendation

Update functype-mcp-server to version 1.4.4 or later, restrict access to MCP tools, and enable authentication.

Related vulnerabilities

Original NVD description (English source)

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@<version>` 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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS