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 <>