CVE-2026-49857

auth-fetch-mcp has an SSRF protection bypass via IPv4-mapped IPv6 loopback. The root cause is in isPrivateV6() handling of hex-normalized IPv4-mapped addresses; input like http://[::ffff:127.0.0.1]:PORT/ becomes http://[::ffff:7f00:1]:PORT/ and net.isIPv4 returns false, allowing requests to priva...

CVE-2026-49857 auth-fetch-mcp has SSRF Protection Bypass via IPv4-mapped IPv6 Loopback

auth-fetch-mcp is an MCP server that lets AI assistants fetch content from authenticated web pages. Version 3.0.1 implements SSRF protection in assertSafeUrl src/security.ts to block requests to private and loopback addresses. However, the isPrivateV6 function fails to detect IPv4-mapped IPv6...

CVE-2026-49857

auth-fetch-mcp is an MCP server that lets AI assistants fetch content from authenticated web pages. Version 3.0.1 implements SSRF protection in assertSafeUrl src/security.ts to block requests to private and loopback addresses. However, the isPrivateV6 function fails to detect IPv4-mapped IPv6...