Dancer2::Plugin::Auth::Extensible versions through 0.713 for Perl allow password reset link poisoning via the request Host header in _default_email_password_reset and _default_welcome_send. Both default emails emit a link of the form `$base/login/$code`, whose authority comes from the request Host header, or from X-Forwarded-Host under behind_proxy (obtained from Dancer2's request->base function). A POST to /login carrying submit_reset and a username needs no authentication: it stores a fresh r