Ticket #55140: 55140.2.patch

src/wp-admin/includes/privacy-tools.php

@@ -138 +138 @@
                                         } else {
                                                 $email_address = $user->user_email;
                                         }
-                                } else {
-                                        $email_address = $username_or_email_address;
+                                } elseif ( is_email( $username_or_email_address ) ) {
+                                        $user = get_user_by( 'email', $username_or_email_address );
+                                        if ( ! $user instanceof WP_User ) {
+                                                add_settings_error(
+                                                        'username_or_email_for_privacy_request',
+                                                        'username_or_email_for_privacy_request',
+                                                        __( 'Unable to add this request. A valid email address or username must be supplied.' ),
+                                                        'error'
+                                                );
+                                        } else {
+                                                $email_address = $user->user_email;
+                                        }
                                 }
 
                                 if ( empty( $email_address ) ) {