The package url-js before 2.1.0 is vulnerable to Improper Input Validation due to improper parsing, which makes it is possible for the hostname to be spoofed. http://\\\\\\\\localhost and http://localhost are the same URL. However, the hostname is not parsed as localhost, and the backslash is reflected as it is.
// cvss v3.1 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None
Checked 2026-10-04 at 01:11 UTC. The most recent advisory here was published 2022-03-12. Updated continuously from NVD, GHSA, OSV and CNA feeds.