{"id":"CVE-2026-59724","title":"Socket.IO enables bidirectional and low-latency communication for every platform","summary":"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 th…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-20","CWE-843"],"vendor":"socket","product":"engine.io","affected":["engine.io >= 6.5.0, < 6.6.7"],"patched":["engine.io 6.6.7"],"published":"2026-07-08","updated":"2026-07-13","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-59724","references":[{"url":"https://github.com/socketio/socket.io/commit/1fa1f46cd420ac5b57bb4c04c959b58f3c79158c","label":"security-advisories@github.com"},{"url":"https://github.com/socketio/socket.io/releases/tag/engine.io@6.6.7","label":"security-advisories@github.com"},{"url":"https://github.com/socketio/socket.io/security/advisories/GHSA-gr94-w7qr-f4j3","label":"security-advisories@github.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-59724.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-59724"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2498128"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-59724"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59724"},{"url":"https://access.redhat.com/errata/RHSA-2026:26994"}],"tags":["nvd","csaf","vex","red-hat"],"epss":0.00609,"epssPercentile":0.48951,"ingestedAt":"2026-07-13T15:27:34.115Z","slug":"CVE-2026-59724","body":"## Overview\n\nSocket.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.\n\n## Affected\n\n- `engine.io >= 6.5.0, < 6.6.7`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `engine.io 6.6.7`\n\n## Vendor advisories\n\n- **RHSA-2026:26994** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-06-18 · [advisory](https://access.redhat.com/errata/RHSA-2026:26994)\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux AI (RHEL AI) 3 · no fix planned: Red Hat Enterprise Linux AI (RHEL AI) 3 · updated 2026-10-06 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-59724.json)","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}