Why React Didn't Kill XSS: The New JavaScript Injection Playbook
Jul 29, 2025
AI Security /Software Engineering
React conquered XSS? Think again. That's the reality facing JavaScript developers in 2025, where attackers have quietly evolved their injection techniques to exploit everything from prototype pollution to AI-generated code, bypassing the very frameworks designed to keep applications secure. Full 47-page guide with framework-specific defenses (PDF, free). JavaScript conquered the web, but with that victory came new battlefields. While developers embraced React, Vue, and Angular, attackers evolved their tactics, exploiting AI prompt injection, supply chain compromises, and prototype pollution in ways traditional security measures can't catch. A Wake-up Call: The Polyfill.io Attack In June 2024, a single JavaScript injection attack compromised over 100,000 websites in the biggest JavaScript injection attack of the year. The Polyfill.io supply chain attack , where a Chinese company acquired a trusted JavaScript library and weaponized it to inject malicious code, affected major pl...