Opera before 11.00 does not clear WAP WML form fields after manual navigation to a new web site, which allows remote attackers to obtain sensitive information via an input field that has the same name as an input field on a previously visited web site.
http://www.opera.com/support/kb/view/979/
http://www.opera.com/docs/changelogs/windows/1100/
http://www.opera.com/docs/changelogs/unix/1100/
http://www.opera.com/docs/changelogs/mac/1100/
http://secunia.com/advisories/42653
http://lists.opensuse.org/opensuse-security-announce/2010-12/msg00006.html