Opera released a security and bug fixes to their desktop browser. The update will bring your Opera up to Opera 12.11 and, as what they have said, will improve the overall stability of the browser. This is a stable release and you can get the update by simply clicking through the Opera Button > Help > Check for updates. The browser should automatically check for a newer version and should also install it for you. You can get Opera 12.11 by downloading it too. Get it from the official Opera download page.