A flaw that allows browsers to enumerate applications on a machine threatens cross-browser anonymity in Chrome, Firefox, Microsoft Edge, Safari and even Tor. A security researcher has discovered a vulnerability that allows websites to track users across a number of different desktop browsers. The vulnerability uses custom URL schemes as an attack vector hence its name. It can assign someone a permanent unique identifier using information about installed apps on that person s computer even if he or she switches browsers, uses incognito mode or accesses the internet through a VPN.
Source: https://threatpost.com/scheme-flooding-website-tracking/166185/