HIGH: fast-uri — fast-uri vulnerable to host confusion via backslash authority introducer
Impact fast-uri v4.1.1 and earlier require a literal // to recognize a URI authority, so a reference that uses \\, /\, or \/ as the authority introducer (in place of //, after an optional scheme) is parsed with no authority: the sequence and everything…
Source fast-uriPublished 9h ago · Aug 3, 2026Posted on Threads

What we hold
- Package
- fast-uri
- Ecosystem
- npm
- Severity
- HIGH
- ID
- CVE-2026-18446
Impact fast-uri v4.1.1 and earlier require a literal // to recognize a URI authority, so a reference that uses \\, /\, or \/ as the authority introducer (in place of //, after an optional scheme) is parsed with no authority: the sequence and everything…