A new attack has been discovered that will cause iOS to restart or respring and macOS to freeze simply by visiting a web page that contains certain CSS & HTML. Windows and Linux users are not affected by this bug.
Some of the recent additions to the Cascading Style Sheets (CSS) web standard are so powerful that a security researcher has abused them to deanonymize visitors to a demo site and reveal their Facebook usernames, avatars, and if they liked a particular web page of Facebook.
With the recent upgrades to the CSS language, CSS code has become a powerful tool that could be abused to track users on websites, extract and steal data from a web page, collect data entered inside form fields (including passwords), and even deanonymize Dark Web users in some scenarios.
Chrome 56 is being rolled out to Windows, Linux, and Mac users and should be available to everyone over the next few days. Along with 56 security updates, this new version comes with quite a few goodies such as HTML5 by default, support for the Sticky position attribute, and the Web Bluetooth API.