Opera before 11.00 does not properly handle security policies during updates to extensions, which might allow remote attackers to bypass intended access restrictions via unspecified vectors.
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