mcp-sanitizer: URL sanitizer allows localhost/IPv6 loopback SSRF bypass via explicit port or bracketed IPv6

影響: npm:mcp-sanitizer < 1.4.0 → 1.4.0

URL sanitizer allows localhost/IPv6 loopback SSRF bypass via explicit port or bracketed IPv6 Summary mcp-sanitizer v1.3.3 fails to block Server-Side Request Forgery (SSRF) targets when a localhost URL includes an explicit port (e.g., http://localhost:8080/) or when an IPv6 loopback/link-local address is expressed in bracketed notation (e.g., http://[::1]:8080/, http://[fe80::1]:8080/). Because the library is explicitly designed to gate MCP tool parameters such as web_fetch and web_scraper befor…

Read on GitHub Advisory Database

On 10/29/2026, 04:51 AM, GitHub Advisory Database published "mcp-sanitizer: URL sanitizer allows localhost/IPv6 loopback SSRF bypass via explicit port or bracketed IPv6" (type: Advisory). Severity is "High" (high). Related technologies: JavaScript / Node.js.