{"id":"CVE-2026-59725","aliases":["GHSA-r635-g3xr-vw7x"],"url":"https://o3.security/vulnerability/CVE-2026-59725","summary":"Socket.IO: Engine.IO Polling Transport Connection Exhaustion","details":"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.","published":"2026-07-08T15:37:52.293Z","modified":"2026-08-12T03:51:14.440516263Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"engine.io","fixedVersion":"6.6.7"}],"fix":{"url":"https://github.com/socketio/socket.io/commit/fc11285e14964c2132d122164bf130c355f60671","label":"socketio/socket.io@fc11285"},"references":[{"type":"WEB","url":"https://github.com/socketio/socket.io/releases/tag/engine.io@6.6.7"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59725.json"},{"type":"ADVISORY","url":"https://github.com/socketio/socket.io/security/advisories/GHSA-r635-g3xr-vw7x"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59725"},{"type":"FIX","url":"https://github.com/socketio/socket.io/commit/fc11285e14964c2132d122164bf130c355f60671"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:14.440516263Z"}}