CVE-2026-40871
mailcow: dockerized is an open source groupware/email suite based on docker. Versions prior to 2026-03b have a second-order SQL injection vulnerability in the quarantine_category field via the Mailcow API. The /api/v1/add/mailbox endpoint stores quarantine_category without validation or sanitization. This value is later used by quarantine_notify.py, which constructs SQL queries using unsafe % string formatting instead of parameterized queries. This results in a delayed (second-order) SQL injection when the quarantine notification job executes, allowing an attacker to inject arbitrary SQL. Using a UNION SELECT, sensitive data (e.g., admin credentials) can be exfiltrated and rendered inside quarantine notification emails. Version 2026-03b fixes the vulnerability.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7.2
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.45%
- Percentil entre todas las CVEs puntuadas: 37
- Fecha de la puntuación: 6/10/2026
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 movement85 % - Impacto principal
T1005Data from Local Systemcollection90 % - Impacto secundario
T1078Valid Accountsstealth · persistence · privilege escalation · initial access70 % - Impacto secundario
T1565.001Stored Data Manipulationimpact75 %
SQL inyección de segundo orden en API remota (AV:N, PR:H). Extrae credenciales admin (T1005) y manipula datos en notificaciones (T1565.001); acceso con altos privilegios (PR:H) permite T1078.
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-20, CWE-89, CWE-116, CWE-564
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-40871",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-40871",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"version": "2.0.3",
"timestamp": "2026-04-21T19:53:34.653739Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.2,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "HIGH",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1.2
}
]
},
"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
{
"vendor": "mailcow",
"product": "mailcow-dockerized",
"versions": [
{
"status": "affected",
"version": "< 2026-03b"
}
]
}
]
}
],
"published": "2026-04-21T20:17:00.527",
"references": [
{
"url": "https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-r8fq-wrfm-cj2q",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-r8fq-wrfm-cj2q",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
],
"vulnStatus": "Deferred",
"weaknesses": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-20"
},
{
"lang": "en",
"value": "CWE-89"
},
{
"lang": "en",
"value": "CWE-116"
},
{
"lang": "en",
"value": "CWE-564"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "mailcow: dockerized is an open source groupware/email suite based on docker. Versions prior to 2026-03b have a second-order SQL injection vulnerability in the quarantine_category field via the Mailcow API. The /api/v1/add/mailbox endpoint stores quarantine_category without validation or sanitization. This value is later used by quarantine_notify.py, which constructs SQL queries using unsafe % string formatting instead of parameterized queries. This results in a delayed (second-order) SQL injection when the quarantine notification job executes, allowing an attacker to inject arbitrary SQL. Using a UNION SELECT, sensitive data (e.g., admin credentials) can be exfiltrated and rendered inside quarantine notification emails. Version 2026-03b fixes the vulnerability."
}
],
"lastModified": "2026-06-17T10:45:48.000",
"sourceIdentifier": "security-advisories@github.com"
}