Updated Aug. 28, 2024. Take back your privacy Firefox is rolling out Total Cookie Protection by default to more Firefox users worldwide, making Firefox the
Sure, but the separate window can be on a different domain. Now you have a way to share cookies across multiple websites on different domains if all of them include an iframe to this external domain. And you can use in-browser messages (see window.postMessage()) to communicate between iframes and main window.
IIRC an iframe contents is treated as a separate window, so cookies aren’t shared either
https://developer.mozilla.org/en-US/docs/Web/API/Window/postMessage
That’s horrific WHY?
Sure, but the separate window can be on a different domain. Now you have a way to share cookies across multiple websites on different domains if all of them include an iframe to this external domain. And you can use in-browser messages (see window.postMessage()) to communicate between iframes and main window.
Indeed see sibling comment https://programming.dev/comment/11983146