Cross-site scripting (XSS) vulnerability in opac-addbybiblionumber.pl in Koha 3.14.x before 3.14.16, 3.16.x before 3.16.12, and 3.20.x before 3.20.1 allows remote attackers to inject arbitrary web script or HTML via a crafted list name.
The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.