704: Sanitizer API with Frederik Braun

The text outlines key strategies and tools for modern web security, focusing on mitigating threats like Cross-Site Scripting (XSS) and improving Content Security Policy (CSP) implementation. XSS prevention emphasizes HTML sanitization through browser-native methods like the setHTML API and libraries such as DOMPurify, which neutralize malicious input. Legacy methods like innerHTML are discouraged due to their vulnerability to attacks. Emerging risks in AI systems, such as prompt injection and harmful outputs from large language models (LLMs), are addressed through sandboxing and input validation.

Content Security Policy (CSP) is highlighted as a powerful defense against XSS and data exfiltration, though its adoption remains low due to complexity and challenges with third-party scripts. Trusted Types are recommended to enforce safer practices by restricting unsafe operations. Modern APIs like setHTML and setHTMLUnsafe aim to simplify secure HTML insertion, while proposals for CSS versioning seek to resolve historical rendering bugs. The text also draws parallels between the success of HTTPS and the need for browser-driven initiatives to automate CSP and XSS protections.

Looking ahead, the vision includes automating security practices through "safe mode" features for HTML and CSS, reducing developer burden. Recommendations stress incremental improvements, such as using setHTML or DOMPurify, and staying informed about evolving standards. Community efforts and open-source tools are emphasized as critical to advancing web security, alongside education and collaboration to address persistent challenges like CSP adoption and AI-specific vulnerabilities.