Description
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.
Published: 2026-09-29
Score: 7.5 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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Tracking

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History

Wed, 30 Sep 2026 21:00:00 +0000

Type Values Removed Values Added
First Time appeared Socket
Socket cluster-engine
Socket socket.io
Vendors & Products Socket
Socket cluster-engine
Socket socket.io

Tue, 29 Sep 2026 17:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 29 Sep 2026 15:30:00 +0000

Type Values Removed Values Added
Description 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.
Title Socket.IO: Prototype Pollution via Unsafe Client Session Lookup
Weaknesses CWE-1321
CWE-20
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Subscriptions

Socket Cluster-engine Socket.io
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-29T16:28:28.476Z

Reserved: 2026-09-29T14:18:02.920Z

Link: CVE-2026-102600

cve-icon Vulnrichment

Updated: 2026-09-29T16:28:20.720Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-29T16:17:06.180

Modified: 2026-09-30T19:38:27.293

Link: CVE-2026-102600

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-30T20:41:34Z

Weaknesses
  • CWE-1321

    Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

  • CWE-20

    Improper Input Validation