Can JavaScript Escape a CSP Meta Tag Inside an Iframe?

· · April 3, 2026, 11:05 p.m.
Summary
This blog post explores the possibility of using CSP (Content Security Policy) meta tags within sandboxed iframes in JavaScript. The author shares their investigation into applying CSP headers in a unique way, revealing that these tags can be injected and effectively control content even when manipulated by untrusted JavaScript. It's a technical exploration that provides insight into web security practices.
AUTHOR