Deluge is a BitTorrent client.
Deluge does not sufficiently sanitize crafted torrent file data, leading to the application interpreting untrusted data as HTML.
An attacker can achieve XSS via a crafted torrent file.
There is no known workaround at this time.
All Deluge users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-p2p/deluge-2.1.1"