A researcher from one of the most well-known fingerprinting scripts, FingerprintJS, has disclosed a vulnerability that allows a website to track a device's user between different browsers, including Chrome, Firefox, Microsoft Edge, Safari, and even Tor.

To perform cross-browser tracking using scheme flooding, a website builds a profile of applications installed on a device by attempting to open their known URL handlers and checking if the browser launches a prompt.

If a prompt is launched to open the application, then it can be assumed that the specific app is installed. By checking for different URL handlers, a script can use the detected applications to build a unique profile for your device.

As the installed applications on a device are the same regardless of the browser you are using, this could allow a script to track a user's browser usage on both Google Chrome and an anonymizing browser such as Tor. 
To test this vulnerability, we visited Darutkin's demo site at schemeflood.com with Microsoft Edge, where a script launches URL handlers for a variety of applications to determine if they are installed.
It is possible that multiple users can have the same combination of installed programs, leading to the same profile ID.