FrontMCP vulnerabilities
3 known CVE vulnerabilities in FrontMCP, translated and rated.
- CVE-2026-59973High
In mcp-from-openapi (2.3.0–2.5.0) and frontmcp and @frontmcp/adapters (1.2.1–1.5.0), loadOpenAPISpec() forwards untrusted OpenAPI URLs and inputs to the tool generator without proper destination validation. The external $ref guard only checks parsed hostname strings without resolving addresses, pinning validated addresses, revalidating redirects, or normalizing IPv4-mapped IPv6. An authenticated user able to import an OpenAPI specification can force requests to internal services.
- CVE-2026-67531Critical
FrontMCP prior to 1.5.7 has a vulnerability in the codecall:execute tool that allows sandbox escape and remote code execution. By exploiting Zod objects, a script can access the Function constructor and execute arbitrary code in the server process. A single tools/call is sufficient to achieve full compromise.
- CVE-2026-39885High
The mcp-from-openapi library in FrontMCP prior to version 2.3.0 does not restrict $ref dereferencing in OpenAPI specifications, enabling SSRF and local file read attacks when processing untrusted specifications.