EUVD-2026-234523

fkie_cve-2022-21676

Engine.IO is the implementation of transport-based cross-browser/cross-device bi-directional communication layer for Socket.IO. A specially crafted HTTP request can trigger an uncaught exception on the Engine.IO server, thus killing the Node.js process. This impacts all the users of the `engine.io` package starting from version `4.0.0`, including those who uses depending packages like `socket.io`. Versions prior to `4.0.0` are not impacted. A fix has been released for each major branch, namely `4.1.2` for the `4.x.x` branch, `5.2.1` for the `5.x.x` branch, and `6.1.1` for the `6.x.x` branch. There is no known workaround except upgrading to a safe version.

GHSA-273r-mgr4-v34f — Uncaught Exception in engine.io

Affected: npm: engine.io

### Impact

A specially crafted HTTP request can trigger an uncaught exception on the Engine.IO server, thus killing the Node.js process.

> RangeError: Invalid WebSocket frame: RSV2 and RSV3 must be clear > at Receiver.getInfo (/.../node_modules/ws/lib/receiver.js:176:14) > at Receiver.startLoop (/.../node_modules/ws/lib/receiver.js:136:22) > at Receiver._write (/.../node_modules/ws/lib/receiver.js:83:10) > at writeOrBuffer (internal/streams/writable.js:358:12)

This impacts all the users of the [`engine.io`](https://www.npmjs.com/package/engine.io) package starting from version `4.0.0`, including those who uses depending packages like [`socket.io`](https://www.npmjs.com/package/socket.io).

### Patches

A fix has been released for each major branch:

| Version range | Fixed version | | --- | --- | | `engine.io@4.x.x` | `4.1.2` | | `engine.io@5.x.x` | `5.2.1` | | `engine.io@6.x.x` | `6.1.1` |

Previous versions (`< 4.0.0`) are not impacted.

For `socket.io` users:

| Version range | `engine.io` version | Needs minor update? | | --- | --- | --- | | `socket.io@4.4.x` | `~6.1.0` | - | `socket.io@4.3.x` | `~6.0.0` | Please upgrade to `socket.io@4.4.x` | `socket.io@4.2.x` | `~5.2.0` | - | `socket.io@4.1.x` | `~5.1.1` | Please upgrade to `socket.io@4.4.x` | `socket.io@4.0.x` | `~5.0.0` | Please upgrade to `socket.io@4.4.x` | `socket.io@3.1.x` | `~4.1.0` | - | `socket.io@3.0.x` | `~4.0.0` | Please upgrade to `socket.io@3.1.x` or `socket.io@4.4.x` (see [here](https://socket…

Most recent entries from all

EUVD-2026-234523

fkie_cve-2022-21676

GHSA-273r-mgr4-v34f — Uncaught Exception in engine.io

gsd-2022-21676