There's a proposed W3C specification for "suborigins" which would allow isolating webapps at a more fine-grained level than the current host:port combination. I

There's a proposed W3C specification for "suborigins" which would allow isolating webapps at a more fine-grained level than the current host:port combination. It'll probably be a good long while before it gets fully standardized and implemented, though. https://w3c.github.io/webappsec-suborigins/ https://w3c.github.io/webappsec-suborigins/