Prototype Pollution in @Socket.io Cluster-Engine
CVE-2026-102600
Socket.IO enables bidirectional and low-latency communication for every platform. Prior to 0.1.1, @socket.io/cluster-engine uses inherited object properties when looking up attacker-controlled session IDs in clustered deployments. Special property names such as __proto__ or constructor can resolve through the object prototype chain instead of identifying an actual connected client, causing the Node.js process to crash and resulting in denial of service. Applications that do not use @socket.io/cluster-engine are not affected. This issue is fixed in version 0.1.1.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- @Socket.io Cluster-Engine — versions < 0.1.1
- Socketio Socket.io — versions < 0.1.1
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-102600?
- CVE-2026-102600 is a high-severity vulnerability in @Socket.io Cluster-Engine, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2026-09-29.
- How severe is CVE-2026-102600?
- High severity. CVSS v3 base score is 7.5 out of 10.