CVE-2026-69185: Socketio Socket.io

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

Socket.IO enables bidirectional and low-latency communication for every platform. Prior to 4.2.7, 3.4.5, and 3.3.6, a specially crafted Socket.IO packet can make the server wait for a large number of binary attachments and buffer them, which can be exploited to make the server run out of memory. This vulnerability is fixed in 4.2.7, 3.4.5, and 3.3.6.

Affected products

• Socketio Socket.io: before 3.3.6 (fixed in 3.3.6); from 3.4.0, before 3.4.5 (fixed in 3.4.5); from 4.0.0, before 4.2.7 (fixed in 4.2.7)

Published 2026-08-03. Last modified 2026-09-10.