UPDATE: Opera has published a response to the reports, claiming that the flaw is no longer active and has been addressed.
"There is no evidence that the vulnerability was ever exploited, and Opera users’ security was never compromised as a result," it said. "It’s also important to note that, as mentioned above, the vulnerability would require the installation of a malicious add-on in order to work. This would be very hard to accomplish on Opera, because we employ manual review in our add-ons store – another measure we take to protect users."
