Ticket #31772: 31772.2.patch

src/wp-admin/js/password-strength-meter.js

@@ -18 +18 @@
                         if (password1 != password2 && password2 && password2.length > 0)
                                 return 5;
 
-                        var result = zxcvbn( password1, blacklist );
+                        // Analyze the strength of the first part of the password.  The 'zxcvbn' library takes a long time to analyse longer passwords.  This causes the browser UI to freeze.
+                        // @todo Update zxcvbn once it analyzes long passwords quickly.
+                        // @see https://github.com/dropbox/zxcvbn/issues/69
+                        var result = zxcvbn( password1.substr(0, 128), blacklist );
                         return result.score;
                 },