ws is an open source WebSocket client and server for Node.js. A request with a number of headers exceeding theserver.maxHeadersCount threshold could be used to crash a ws server. The vulnerability was fixed in ws@8.17.1 (e55e510) and backported to ws@7.5.10 (22c2876), ws@6.2.3 (eeb76d3), and ws@5.2.4 (4abd8f6). In vulnerable versions of ws, the issue can be mitigated in the following ways: 1. Reduce the maximum allowed length of the request headers using the --max-http-header-size=size and/or the maxHeaderSize options so that no more headers than the server.maxHeadersCount limit can be sent. 2. Set server.maxHeadersCount to 0 so that no limit is applied.