The firefox and tor devs are cooperating to upstream a tor browser feature that isolates cookie stores and similar things based on the domain shown in the URL

The firefox and tor devs are cooperating to upstream a tor browser feature that isolates cookie stores and similar things based on the domain shown in the URL bar[0]. Available in nightly by enabling privacy.firstparty.isolate = true in about:config. Additionally they're also also working on a more customizable version of that called contextual identities[1], which eventually will also be manageable by extensions[2] And of course addons that block cookies in cross-origin requests or cross origin requests in general such as µmatrix[3] also plug this hole. [0] https://bugzilla.mozilla.org/show_bug.cgi?id=1260931 https://bugzilla.mozilla.org/show_bug.cgi?id=1260931 [1] https://blog.mozilla.org/tanvi/2016/06/16/contextual-identities-on-the-web/ https://blog.mozilla.org/tanvi/2016/06/16/contextual-identit... [2] https://bugzilla.mozilla.org/show_bug.cgi?id=1302697 https://bugzilla.mozilla.org/show_bug.cgi?id=1302697 [3] https://github.com/gorhill/uMatrix https://github.com/gorhill/uMatrix