Ticket #43285: 43285.patch

misc.php

@@ -1146 +1146 @@
  * @since 4.9.0
  */
 function wp_admin_headers() {
-        $policy = 'same-origin';
+        $policy = 'strict-origin-when-cross-origin';
 
         /**
          * Filters the admin referrer policy header value. Default 'same-origin'.