youtube bbcode exploitable?

[jesus likes pie]

I've heard that having a youtube bbcode or other thing like that could make the site more vulnerable to exploits.

Is this true? Is it really something I should be worried about?

I am currently looking at this:

https://vborg.vbsupport.ru/showthread.php?t=201698

It doesn't use the <embed> tags which I believe were the original culprits.

[Dismounted]

The only thing I would worry about is the inclusion of foreign flash files. However, if the modification is properly constructed, this shouldn't happen.