EUVD-2026-42312

Socket.IO enables bidirectional and low-latency communication for every platform. From 6.5.0 before 6.6.7, Engine.IO servers with WebTransport enabled can resolve a crafted session ID such as proto through an inherited property of the clients object during WebTransport upgrade handling, causing a...

PT-2026-56487

Name of the Vulnerable Software and Affected Versions Socket.IO versions 6.5.0 through 6.6.6 Description Engine.IO servers with WebTransport enabled are susceptible to a denial of service. During WebTransport upgrade handling, the server can resolve a crafted session ID, such as proto , through a...

engine.io: Engine.IO: Denial of Service via crafted WebTransport session ID

A flaw was found in Engine.IO. When Engine.IO servers have WebTransport enabled, a remote attacker can craft a session ID to resolve an inherited property of the clients object during WebTransport upgrade handling. This can lead to a TypeError, resulting in a denial of service DoS for the server...