CVE-2026-59724

Socket.IO’s Engine.IO component is affected in versions 6.5.0–6.6.6 when WebTransport is enabled. During a WebTransport upgrade, processing a crafted session ID such as proto on an inherited property of the clients object can trigger a TypeError, leading to a denial of service. The issue has been...

CVE-2026-59725

CVE-2026-59725 affects Socket.IO’s Engine.IO polling transport (versions 4.1.0–6.6.6). The root cause is that invalid binary POST requests with Content-Type: application/octet-stream are not properly closing the HTTP response, enabling unauthenticated attackers to exhaust server-side connections ...