CVE-2026-86009
Mailu es un servidor de correo distribuido como un conjunto de imágenes de Docker. Antes de f05aeb8322e2f61096af6b089d61ba6f40587d96, los gestores de dominios pueden habilitar la suplantación de identidad (spoofing) para dominios alojados que no controlan. Un administrador de dominio potencialmente malicioso habilita la suplantación para otro dominio alojado y puede enviar correos autenticados con DKIM/SPF para dominios para los que no debería tener permiso. Esta vulnerabilidad se corrige con f05aeb8322e2f61096af6b089d61ba6f40587d96.
Traducción automática del texto original de NVD (en inglés).
CVSS
- Puntuación base
- 8.2
- Versión
- 4.0
- Vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días
- 0.30 %
- Percentil entre todas las CVEs puntuadas
- 21
- Fecha de la puntuación
- 21/10/2026
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
T1210Exploitation of Remote Serviceslateral movement60 % - Impacto principal
T1078Valid Accountsstealth · persistence · privilege escalation · initial access55 %
Inferido por reglas deterministas a partir del vector CVSS y la CWE. Solo orientativo.
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-285, CWE-863
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-86009",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-86009",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-10-21T02:26:25.611618Z"
}
}
],
"cvssMetricV40": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"cvssData": {
"Safety": "NOT_DEFINED",
"version": "4.0",
"Recovery": "NOT_DEFINED",
"baseScore": 8.2,
"Automatable": "NOT_DEFINED",
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"exploitMaturity": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"privilegesRequired": "HIGH",
"subIntegrityImpact": "HIGH",
"vulnIntegrityImpact": "HIGH",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"vulnAvailabilityImpact": "NONE",
"availabilityRequirement": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"subConfidentialityImpact": "NONE",
"vulnConfidentialityImpact": "NONE",
"confidentialityRequirement": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED"
}
}
]
},
"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
{
"vendor": "Mailu",
"product": "Mailu",
"versions": [
{
"status": "affected",
"version": "< f05aeb8322e2f61096af6b089d61ba6f40587d96"
}
]
}
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}
],
"published": "2026-10-16T17:17:51.920",
"references": [
{
"url": "https://github.com/Mailu/Mailu/commit/f05aeb8322e2f61096af6b089d61ba6f40587d96",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/Mailu/Mailu/issues/2686",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/Mailu/Mailu/pull/4072",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/Mailu/Mailu/security/advisories/GHSA-crww-m82r-2wfm",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/Mailu/Mailu/issues/2686",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
],
"vulnStatus": "Deferred",
"weaknesses": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-285"
},
{
"lang": "en",
"value": "CWE-863"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Mailu is a mail server distributed as a set of Docker images. Prior to f05aeb8322e2f61096af6b089d61ba6f40587d96, domain managers can enable spoofing for hosted domains they do not control. A potentially malicious domain administrator enables spoofing for another hosted domain and can send emails that are authenticated with DKIM/SPF for domains they should not be able to. This vulnerability is addressed by f05aeb8322e2f61096af6b089d61ba6f40587d96."
}
],
"lastModified": "2026-10-21T03:17:19.877",
"sourceIdentifier": "security-advisories@github.com"
}