The Opera desktop team has released Opera 12.17 for Windows, which has fixed the Heartbleed bug, Mac and Linux versions are not affected. Though the Presto engine used in Opera 12 is not vulnerable to the bug, but autoupdater used for the browser is. "The standalone autoupdater for Opera 12 on Windows was vulnerable to a Heartbleed attack from someone who would be in possession of a valid Opera certificate." said Sigbjørn Vik, developer in a blog post.

Opera 12.17 direct download links

Apart from this, Opera team has fixed another security bug, so this  is a necessary security upgrade for Opera Presto, you can download the same from below.

"Wile fixing this, we also found another issue with our autoupdate on Windows which might be exploited by someone in possession of such a certificate. Successful exploitation, which would require using a third, unrelated bug on Windows, could allow a mischievous man in the middle to run arbitrary code on the computer." he added.

Opera 12.17 (x86)

Opera 12.17   (x64)