CVE-2026-16221 fast-uri vulnerable to host confusion via literal backslash authority delimiter

Impact: fast-uri versions from 2.3.1 through 4.1.0 including the 3.x line up to 3.1.3 and the 2.x line up to 2.4.2 do not treat a literal backslash character U+005C as an authority delimiter. Node's native WHATWG URL parser, used by fetch, undici, and Node's http and https clients, normalizes the...