CVE-2026-80347 mcp-fetch through 1.6.3 Server-Side Request Forgery via Unstripped IPv6 Literal Brackets

mcp-fetch checks a fetch target against its SSRF guard without removing the brackets that surround an IPv6 literal. isSafeUrl reads the hostname from the parsed URL, which for a literal such as http://::1/ yields the bracketed string, and then tests it with net.isIP. That call returns zero for a...

CVE-2026-80347

mcp-fetch (npm package @kazuph/mcp-fetch ) through version 1.6.3 contains a Server-Side Request Forgery (SSRF) flaw in its isSafeUrl guard. When a target URL uses an IPv6 literal such as http://[::1]/, the parsed hostname retains the surrounding brackets. The net.isIP check returns zero for the b...