gov.uk · Headers
No Cross-Origin-Opener-Policy
A window this page opens, or one that opened it, keeps a handle on it that can be misused.
- Send the header below; use same-origin-allow-popups if the site opens sign-in or payment windows.
Cross-Origin-Opener-Policy: same-originWhat it checks
The Cross-Origin-Opener-Policy header.
Why it matters
It cuts the link between this page and windows it opens or that opened it, which other sites can misuse.