CVE-2024-38355

Unhandled 'error' event in socket.io

CVSS 3.1 7.3 HIGHEUVD CVSS 3.1 7.3 CVSS 3.1 · [email protected] · Secondary 7.3 HIGHCVSS_V3 CVSS_V4 Publisher rating MODERATEFixed by socket.io 2.5.1 Fixed by socket.io 4.6.2KEV status unknown

Original advisory

cve-program · CVE-2024-38355

Published

Socket.IO is an open source, real-time, bidirectional, event-based, communication framework. A specially crafted Socket.IO packet can trigger an uncaught exception on the Socket.IO server, thus killing the Node.js process. This issue is fixed by commit `15af22fc22` which has been included in `[email protected]` (released in May 2023). The fix was backported in the 2.x branch as well with commit `d30630ba10`. Users are advised to upgrade. Users unable to upgrade may attach a listener for the "error" event to catch these errors.

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euvd · EUVD-2024-1878

Published

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nvd · CVE-2024-38355

Published

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osv · GHSA-25hc-qcg6-38wj

Published

### Impact A specially crafted Socket.IO packet can trigger an uncaught exception on the Socket.IO server, thus killing the Node.js process. ``` node:events:502 throw err; // Unhandled 'error' event ^ Error [ERR_UNHANDLED_ERROR]: Unhandled error. (undefined) at new NodeError (node:internal/errors:405:5) at Socket.emit (node:events:500:17) at /myapp/node_modules/socket.io/lib/socket.js:531:14 at process.processTicksAndRejections (node:internal/process/task_queues:77:11) { code: 'ERR_UNHANDLED_ERROR', context: undefined } ``` ### Affected versions | Version range | Needs minor update? | |------------------|------------------------------------------------| | `4.6.2...latest` | Nothing to do | | `3.0.0...4.6.1` | Please upgrade to `[email protected]` (at least) | | `2.3.0...2.5.0` | Please upgrade to `[email protected]` | ### Patches This issue is fixed by https://github.com/socketio/socket.io/commit/15af22fc22bc6030fcead322c106f07640336115, included in `[email protected]` (released in May 2023). The fix was backported in the 2.x branch today: https://github.com/socketio/socket.io/commit/d30630ba10562bf987f4d2b42440fc41a828119c ### Workarounds As a workaround for the affected versions of the `socket.io` package, you can attach a listener for the "error" event: ```js io.on("connection", (socket) => { socket.on("error", () => { // ... }); }); ``` ### For more information If you have any questions or comments about this advisory: - Open a discussion [here](https://github.com/socketio/socket.io/discussions) Thanks a lot to [Paul Taylor](https://github.com/Y0ursTruly) for the responsible disclosure. ### References - https://github.com/socketio/socket.io/commit/15af22fc22bc6030fcead322c106f07640336115 - https://github.com/socketio/socket.io/commit/d30630ba10562bf987f4d2b42440fc41a828119c

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Affected versions, risk and source history

Exploitation and risk

Source status

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Risk history

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Advisory history

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13 Nov 2026 01:33:15 UTC