Browser & Web Performance · Senior · Question 5 of 75

What does `Cross-Origin-Opener-Policy: same-origin` protect against, besides enabling isolation?

✓Correct answer: Cross-origin windows opened by or opening your page losing their window.opener reference, which blocks many XS-Leaks and tabnabbing
2Scripts from other origins being downloaded
3Other sites embedding your page in an iframe

Explanation

Popups put in a separate browsing context group can't count your frames, navigate you or measure timings via the window handle.

Further reading

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