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 <>