CVE-2026-59724 — Socket.IO: Engine.IO WebTransport SID DoS
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 sess…
Published: 2026-07-08 · CVSS: 7.5 · CVSS 3.1
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 TypeError and denial of service. This issue is fixed in version 6.6.7.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7