Description
ws is an open source WebSocket client and server library for Node.js. A specially crafted value of the `Sec-Websocket-Protocol` header can be used to significantly slow down a ws server. The vulnerability has been fixed in ws@7.4.6 (https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff). In vulnerable versions of ws, the issue can be mitigated by reducing the maximum allowed length of the request headers using the [`--max-http-header-size=size`](https://nodejs.org/api/cli.html#cli_max_http_header_size_size) and/or the [`maxHeaderSize`](https://nodejs.org/api/http.html#http_http_createserver_options_requestlistener) options.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| websockets | ws | >= 5.0.0 <= 7.4.5 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | node-ws | 7.4.2+~cs18.0.8-2 | — |
| Debian 13 | node-ws | 7.4.2+~cs18.0.8-2 | — |
| Debian 12 | node-ws | 7.4.2+~cs18.0.8-2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | node-ws | No fix yet | — |
| Ubuntu 20.04 LTS | node-ws | No fix yet | — |
| Ubuntu 18.04 LTS | node-ws | No fix yet | — |
| Ubuntu 16.04 LTS | node-ws | No fix yet | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | js-jquery | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| npm | ws | >= 7.0.0, < 7.4.6 | 7.4.6 | GHSA-6fc8-4gx4-v693 |
| npm | ws | >= 6.0.0, < 6.2.2 | 6.2.2 | GHSA-6fc8-4gx4-v693 |
| npm | ws | >= 5.0.0, < 5.2.3 | 5.2.3 | GHSA-6fc8-4gx4-v693 |
Advisories 1
- WID-SEC-2026-2948 HCL BigFix AEX: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Aug 20, 2026
References
- https://github.com/websockets/ws/security/advisories/GHSA-6fc8-4gx4-v693
- https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff
- [tinkerpop-commits] 20210701 [tinkerpop] 01/03: Bumped ws to 6.2.2 to address CVE-2021-32640 CTR mailing-list
- https://security.netapp.com/advisory/ntap-20210706-0005/