Is it possible to load a sanboxed iframe that can run scripts and write cookies but they don't overwrite the parent's cookies?
For example outer HTML will look like this:
outer.html
<html>
.....
<script>document.cookie='page=outer; path=/';</script>
<iframe sandbox="<attribute-here>" src="./inner.html"></iframe>
.....
</html>
inner.html
<html>
.....
<script>document.cookie='page=inner; path=/';</script>
.....
</html>
The desired result is that the outer page always remains with the cookie value outer and the inner one has the value inner