I think your approach of trying to filter out common known attacks will be a constant battle. Instead of attempting that, why don't you simply HTML-filter attack? Usernames should not contain (or be interpolated as) HTML. See for example homoglyph attacks like tye&nbsbp; which really, really looks like tye but with whitespace at the end.

In reply to Re: Input Validation for Template Toolkit by Corion
in thread Input Validation and pattern matching in Template Toolkit by dipit

Title:
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