CVE-2026-18446 fast-uri vulnerable to host confusion via backslash authority introducer

fast-uri before 4.1.2, 3.1.5, and 2.4.4 requires a literal double forward slash to recognize a URI authority, so a reference that uses a backslash based introducer in place of it backslash backslash, forward slash backslash, or backslash forward slash is parsed with no authority and folds into th...

CVE-2026-18446

CVE-2026-18446 affects the fast-uri library prior to versions 4.1.2, 3.1.5, and 2.4.4 . A backslash-based introducer can substitute for a literal double forward slash required to recognize a URI authority, causing fast-uri to misparse the host while Node’s WHATWG URL parser treats backslashes dif...