Product
auth-fetch-mcp versions up to and including 3.0.1 contain an SSRF protection bypass vulnerability (CVE-2026-49857) where the `isPrivateV6()` function fails to correctly identify IPv4-mapped IPv6 loopback addresses after Node.js URL normalization, allowing URLs like `http://[::ffff:127.0.0.1]:PORT/` to bypass the `assertSafeUrl()` check, enabling an attacker to coerce the `auth_fetch` or `download_media` tools to make requests to internal or loopback services and compromising the confidentiality of internal service responses.