CVE Catalog

CVE-2026-102599

High
Published: —Translated: NVD NIST

Summary

A denial-of-service vulnerability exists in Engine.IO / Socket.IO servers that allow transport upgrades. The Engine.IO protocol revision is negotiated during the initial handshake and stored on the session, but a newly-created transport, including a WebSocket upgrade transport, could be exploited to overload the server.

Risk Assessment

An attacker can cause service unavailability, potentially disrupting application operations and impacting business continuity.

Recommendation

Update Engine.IO / Socket.IO servers to a patched version or restrict transport upgrades if feasible.

Related vulnerabilities

Original NVD description (English source)

### Impact A denial-of-service vulnerability exists in Engine.IO / Socket.IO servers that allow transport upgrades. The Engine.IO protocol revision is negotiated during the initial handshake and stored on the session, but a newly-created transport, including a WebSocket upgrade transport, could in

Vulnerability data from NVD (NIST) · CISA KEV · EPSS