filebrowser before v2.63.21 Access Rule Bypass via Path Canonicalization

filebrowser versions before v2.63.21 fail to canonicalize paths before evaluating access rules, allowing authenticated users to bypass administrator-defined deny rules using case-variant or backslash-separated paths. Attackers can request files with alternate path representations that match no rule but resolve to the same filesystem object, gaining unauthorized access to denied files within their scope.