CVE-2026-56862
Handshake messages, such as KeyUpdate, are always considered as state-advancing, regardless of whether a handshake has been completed or not. As a result, a malicious client can keep sending KeyUpdate messages to force the server to keep performing key derivation operations indefinitely.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 7.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.57%
- Percentil entre todas las CVEs puntuadas: 45
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1190Exploit Public-Facing Applicationinitial access85 % - Impacto principal
T1499.004Application or System Exploitationimpact90 %
AV:N/AC:L/PR:N indica red sin autenticación (T1190). El atacante envía KeyUpdate indefinidamente forzando operaciones de derivación de claves, causando exhaustión de recursos del servidor (DoS/T1499.004 por consumo de CPU).
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
CWE
- CWE-770
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-56862",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-56862",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-08-14T15:27:34.651997Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.5,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "security@golang.org",
"affectedData": [
{
"vendor": "Go standard library",
"product": "crypto/tls",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "1.25.13",
"versionType": "semver"
},
{
"status": "affected",
"version": "1.26.0-0",
"lessThan": "1.26.6",
"versionType": "semver"
},
{
"status": "affected",
"version": "1.27.0-0",
"lessThan": "1.27.0-rc.3",
"versionType": "semver"
}
],
"packageName": "crypto/tls",
"collectionURL": "https://pkg.go.dev",
"defaultStatus": "unaffected",
"programRoutines": [
{
"name": "Conn.readRecordOrCCS"
},
{
"name": "Conn.Handshake"
},
{
"name": "Conn.HandshakeContext"
},
{
"name": "Conn.Read"
},
{
"name": "Conn.Write"
},
{
"name": "Dial"
},
{
"name": "DialWithDialer"
},
{
"name": "Dialer.Dial"
},
{
"name": "Dialer.DialContext"
},
{
"name": "QUICConn.HandleData"
},
{
"name": "QUICConn.Start"
}
]
}
]
}
],
"published": "2026-08-13T22:17:22.550",
"references": [
{
"url": "https://go.dev/cl/804261",
"source": "security@golang.org"
},
{
"url": "https://go.dev/issue/80528",
"source": "security@golang.org"
},
{
"url": "https://groups.google.com/g/golang-announce/c/94pEornpRlI",
"source": "security@golang.org"
},
{
"url": "https://pkg.go.dev/vuln/GO-2026-6090",
"source": "security@golang.org"
}
],
"vulnStatus": "Awaiting Analysis",
"weaknesses": [
{
"type": "Secondary",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"description": [
{
"lang": "en",
"value": "CWE-770"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Handshake messages, such as KeyUpdate, are always considered as state-advancing, regardless of whether a handshake has been completed or not. As a result, a malicious client can keep sending KeyUpdate messages to force the server to keep performing key derivation operations indefinitely."
}
],
"lastModified": "2026-09-03T16:37:52.170",
"sourceIdentifier": "security@golang.org"
}