What do you mean by that? Do you mean your users can post <script> tags in their posts and they are then embedded in the forum code instead of being unparsed and displayed as plane text?
Then maybe the links bellow will help you out.
https://www.vbulletin.com/docs/html/...lacements_html
https://www.vbulletin.com/docs/html/main/options_bbcode
Code:
# Allow HTML in Non Forum Specific Areas
Allow users to include raw HTML code in Non Forum Specific Areas?
Warning:
Enabling this setting is strongly not recommended.