{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:socket:engine.io:*:*:*:*:*:node.js:*:*",
            "extracted_events": [
              {
                "introduced": "4.1.0"
              },
              {
                "fixed": "6.6.7"
              }
            ],
            "source": [
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "fb6b0efec9fcc154dc9131189d78fcfa0a6c7f46"
            },
            {
              "fixed": "439a8f669c6788b512dd76011c4476830d67515b"
            },
            {
              "fixed": "fc11285e14964c2132d122164bf130c355f60671"
            }
          ],
          "repo": "https://github.com/socketio/socket.io",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-r635-g3xr-vw7x"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-404"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59725.json"
  },
  "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.",
  "id": "CVE-2026-59725",
  "modified": "2026-07-16T03:31:00.153900978Z",
  "published": "2026-07-08T15:37:52.293Z",
  "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"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Socket.IO: Engine.IO Polling Transport Connection Exhaustion"
}