CVE-2026-81563
A BIND resolver encountering an SVCB/HTTPS AliasMode record referencing 14 or more SVCB/HTTPS ServiceMode records may fail to properly deallocate internal resources. If this happens repeatedly, resource exhaustion will eventually prevent the resolver from performing new recursive lookups. This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
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 %
Vulnerabilidad de agotamiento de recursos (CWE-401) en BIND resolver accesible en red; procesamiento de registros SVCB/HTTPS provoca fallo de desasignación causando DoS por exhaustión de recursos internos.
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
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-401
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-81563",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-81563",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-09-17T17:47:13.244761Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security-officer@isc.org",
"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-officer@isc.org",
"affectedData": [
{
"vendor": "ISC",
"product": "BIND 9",
"versions": [
{
"status": "affected",
"version": "9.18.0",
"versionType": "custom",
"lessThanOrEqual": "9.18.50"
},
{
"status": "affected",
"version": "9.20.0",
"versionType": "custom",
"lessThanOrEqual": "9.20.27"
},
{
"status": "affected",
"version": "9.21.0",
"versionType": "custom",
"lessThanOrEqual": "9.21.25"
},
{
"status": "affected",
"version": "9.18.11-S1",
"versionType": "custom",
"lessThanOrEqual": "9.18.50-S1"
},
{
"status": "affected",
"version": "9.20.9-S1",
"versionType": "custom",
"lessThanOrEqual": "9.20.27-S1"
}
],
"defaultStatus": "unaffected"
}
]
}
],
"published": "2026-09-16T14:17:10.543",
"references": [
{
"url": "https://downloads.isc.org/isc/bind9/9.20.29",
"source": "security-officer@isc.org"
},
{
"url": "https://downloads.isc.org/isc/bind9/9.21.26",
"source": "security-officer@isc.org"
},
{
"url": "https://kb.isc.org/docs/cve-2026-81563",
"source": "security-officer@isc.org"
}
],
"vulnStatus": "Awaiting Analysis",
"weaknesses": [
{
"type": "Secondary",
"source": "security-officer@isc.org",
"description": [
{
"lang": "en",
"value": "CWE-401"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "A BIND resolver encountering an SVCB/HTTPS AliasMode record referencing 14 or more SVCB/HTTPS ServiceMode records may fail to properly deallocate internal resources. If this happens repeatedly, resource exhaustion will eventually prevent the resolver from performing new recursive lookups.\nThis issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1."
}
],
"lastModified": "2026-09-17T18:17:09.147",
"sourceIdentifier": "security-officer@isc.org"
}