Opera has reported a protocol vulnerability that impinge on connection security when the connection is renegotiated.

A vulnerability has been reported in current versions of SSL and TLS protocols, involving a lack of cryptographic association between original set of security parameters and the one resulting after renegotiation. This condition may allow an attacker to inject data and instructions into the HTTPS connection, triggering unauthorized transactions made under the user's name.

Update to Opera 10.50 or later versions

Advisory: TLS protocol vulnerable to Man In The Middle attack (http://www.opera.com/support/kb/view/944/)