{"id":"CVE-2026-59725","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 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-Ty…","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-404","CWE-772"],"vendor":"socket","product":"engine.io","affected":["engine.io >= 4.1.0, < 6.6.7"],"patched":["engine.io 6.6.7"],"published":"2026-07-08","updated":"2026-10-14","sourceUpdated":"2026-10-14T19:17:18.100","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-59725","references":[{"url":"https://github.com/socketio/socket.io/commit/fc11285e14964c2132d122164bf130c355f60671","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-r635-g3xr-vw7x","label":"security-advisories@github.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-59725.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-59725"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2498118"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-59725"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59725"},{"url":"https://access.redhat.com/errata/RHSA-2026:37577"},{"url":"https://access.redhat.com/errata/RHSA-2026:42986"}],"tags":["nvd","csaf","vex","red-hat","cve.org"],"epss":0.00636,"epssPercentile":0.50298,"ingestedAt":"2026-07-13T15:27:34.133Z","ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-07-08T16:50:45.800976Z"},"slug":"CVE-2026-59725","body":"## Overview\n\nSocket.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.\n\n## Affected\n\n- `engine.io >= 4.1.0, < 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-2026:37577** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-07-10 · [advisory](https://access.redhat.com/errata/RHSA-2026:37577)\n- **RHSA-2026:42986** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-07-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:42986)\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-2026-59725.json)","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}