Simon Willison’s Weblog

24th January 2009 - Link Blog

OWASP: XSS Prevention Cheat Sheet. Comprehensive set of rules for avoiding XSS—there’s a bit more to it than just escaping all output variables, since you have to take markup context in to account.

Posted 24th January 2009 at 11:58 pm

Recent articles

Conceptual integrity and counting lines of code - 19th August 2026
Qwen 3.8 27B is excellent, but it defaults to wildly overthinking things - 16th August 2026
Now we have a timeline of the OpenAI accidental attack against Hugging Face - 7th August 2026

This is a link post by Simon Willison, posted on 24th January 2009.

markup 8 owasp 4 security 627 xss 60

Monthly briefing

Sponsor me for $10/month and get a curated email digest of the month's most important LLM developments.

Pay me to send you less!

Sponsor & subscribe