This should be stripped/escaped in safe_mode.

<script> alert("Hello world!") </script>

With blank lines.

<script> alert("Hello world!") </script>

Now with some weirdness

<script <!-- alert("Hello world!") </script <> `

Try another way.

<script <!-- alert("Hello world!") </script <> This time with blank lines. <script <!-- alert("Hello world!") </script <>