Socket.IO enables bidirectional and low-latency communication for every platform. From 4.1.0 before 6.6.7, Engine.IO protocol v4 polling transport does not properly close the HTTP response for invalid binary POST requests with Content-Type: application/octet-stream, allowing an unauthenticated attacker to exhaust server-side connections and sockets. This issue is fixed in version 6.6.7.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://github.com/socketio/socket.io/commit/fc11285e14964c2132d122164bf130c355f60671 Patch
- https://github.com/socketio/socket.io/security/advisories/GHSA-r635-g3xr-vw7x Patch, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 7.5 · socketNVD modified 2026-10-14 19:17
Affected (CPE criteria) 1
cpe:2.3:a:socket:engine.io:*:*:*:*:*:node.js:*:*