All Security Checks
HeadersMedium PriorityPro
Cross-Origin-Opener-Policy
COOP isolates your browsing context from cross-origin documents, preventing certain cross-origin attacks.
Why It Matters
Prevents cross-origin documents from accessing your window object, protecting against certain side-channel attacks and window.opener exploits.
How We Check
We verify COOP header presence and check for secure values like same-origin or same-origin-allow-popups.
How to Fix
Add Cross-Origin-Opener-Policy: same-origin for full isolation. Use same-origin-allow-popups if you need popup functionality.
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