What’s Vulnerable › Vulnerabilities

CVE-2022-41940: Uncaught exception in engine.io

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.1% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2022-11-22 · updated 2026-06-17
• Weakness: CWE-248

Description

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, including those who uses depending packages like socket.io. There is no known workaround except upgrading to a safe version. There are patches for this issue released in versions 3.6.1 and 6.2.1.

Affected products

• socketio engine.io: before 3.6.1; from 4.0.0 before 6.2.1 — fixed in 3.6.1, 6.2.1

How to fix

Upgrade to a fixed version: socketio engine.io 3.6.1, 6.2.1. Check the vendor advisory for mitigations.

References

• https://github.com/socketio/engine.io/commit/425e833ab13373edf1dd5a0706f07100db14e3c6
• https://github.com/socketio/engine.io/commit/83c4071af871fc188298d7d591e95670bf9f9085
• https://github.com/socketio/engine.io/security/advisories/GHSA-r7qp-cfhv-p84w
• https://github.com/socketio/engine.io/commit/425e833ab13373edf1dd5a0706f07100db14e3c6
• https://github.com/socketio/engine.io/commit/83c4071af871fc188298d7d591e95670bf9f9085
• https://github.com/socketio/engine.io/security/advisories/GHSA-r7qp-cfhv-p84w

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