In PHP versions 7.3.x below 7.3.26, 7.4.x below 7.4.14 and 8.0.0, when validating URL with functions like filter_var($url, FILTER_VALIDATE_URL), PHP will accept an URL with invalid password as valid URL. This may lead to functions that rely on URL being valid to mis-parse the URL and produce wrong data as components of the URL.