Description
Engine.IO is the implementation of transport-based cross-browser/cross-device bi-directional communication layer for Socket.IO. An uncaught exception vulnerability was introduced in version 5.1.0 and included in version 4.1.0 of the `socket.io` parent package. Older versions are not impacted. 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 use depending packages like `socket.io`. This issue was fixed in version 6.4.2 of Engine.IO. There is no known workaround except upgrading to a safe version.
Scores
CVSS v3
6.5
EPSS
0.0094
EPSS Percentile
76.3%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-248
Status
published
Products (2)
npm/engine.io
5.1.0 - 6.4.2npm
socket/engine.io
5.1.0 - 6.4.2
Published
May 08, 2023
Tracked Since
Feb 18, 2026