CVE-2026-59724
Full vulnerability record from the local CVENow database.
Description
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.
Severity
HIGH
CVSS score
7.5
(v3.1)
Vulnerability status
Analyzed
Source identifier
Published
2026-07-08 16:16:32.980000
Last modified
2026-10-25 20:10:00.147000
View original CVE JSON
{
"id": "CVE-2026-59724",
"sourceIdentifier": "[email protected]",
"published": "2026-07-08T16:16:32.980",
"lastModified": "2026-10-25T20:10:00.147",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "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."
},
{
"lang": "es",
"value": "Socket.IO permite la comunicación bidireccional y de baja latencia para todas las plataformas. Desde la versión 6.5.0 hasta la 6.6.7, los servidores de Engine.IO con WebTransport habilitado pueden resolver un ID de sesión manipulado, como __proto__, a través de una propiedad heredada del objeto clients durante el manejo de la actualización de WebTransport, causando un TypeError y denegación de servicio. Este problema se corrige en la versión 6.6.7."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "socketio",
"product": "socket.io",
"versions": [
{
"version": ">= 6.5.0, < 6.6.7",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 3.9,
"impactScore": 3.6
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-07-08T17:58:43.578991Z",
"id": "CVE-2026-59724",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-20"
}
]
},
{
"source": "[email protected]",
"type": "Primary",
"description": [
{
"lang": "en",
"value": "NVD-CWE-noinfo"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:a:socket:engine.io:*:*:*:*:*:node.js:*:*",
"versionStartIncluding": "6.5.0",
"versionEndExcluding": "6.6.7",
"matchCriteriaId": "96612FDE-E815-461C-9ABA-08B2979A8698"
}
]
}
]
}
],
"references": [
{
"url": "https://github.com/socketio/socket.io/commit/1fa1f46cd420ac5b57bb4c04c959b58f3c79158c",
"source": "[email protected]",
"tags": [
"Patch"
]
},
{
"url": "https://github.com/socketio/socket.io/releases/tag/[email protected]",
"source": "[email protected]",
"tags": [
"Release Notes"
]
},
{
"url": "https://github.com/socketio/socket.io/security/advisories/GHSA-gr94-w7qr-f4j3",
"source": "[email protected]",
"tags": [
"Patch",
"Vendor Advisory",
"Mitigation"
]
}
]
}