CVE-2026-107121
A flaw was found in the SMTP email configuration handling of the keycloak-services component. When the STARTTLS option is enabled, Keycloak fails to strictly enforce an encrypted connection, allowing it to fall back to unencrypted communication if the encryption request is tampered with. An attacker who can intercept network traffic can exploit this to capture sensitive email credentials and message content in plain text.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
- Puntuación base: 6.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.08%
- Percentil entre todas las CVEs puntuadas: 0
- Fecha de la puntuación: 7/10/2026
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
T1557Adversary-in-the-Middlecredential access · collection90 % - Impacto principal
T1212Exploitation for Credential Accesscredential access85 % - Impacto secundario
T1005Data from Local Systemcollection75 %
CWE-319 (improper encryption) + STARTTLS fallback en red (AV:N) permite interceptación de credenciales y mensajes. T1557 (MITM) es la técnica de explotación; T1212 (credential access) y T1005 (data from local system) son impactos.
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-319
Referencias
JSON original (NVD)
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{
"id": "CVE-2026-107121",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Primary",
"source": "secalert@redhat.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 6.5,
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N",
"integrityImpact": "LOW",
"userInteraction": "NONE",
"attackComplexity": "HIGH",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 4.2,
"exploitabilityScore": 2.2
}
]
},
"affected": [
{
"source": "secalert@redhat.com",
"affectedData": [
{
"cpes": [
"cpe:/a:redhat:build_keycloak:"
],
"vendor": "Red Hat",
"product": "Red Hat Build of Keycloak",
"packageName": "keycloak-services",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "affected"
},
{
"cpes": [
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],
"vendor": "Red Hat",
"product": "Red Hat Build of Keycloak",
"packageName": "rhbk/keycloak-rhel9",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "affected"
},
{
"cpes": [
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],
"vendor": "Red Hat",
"product": "Red Hat Single Sign-On 7",
"packageName": "keycloak-services",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "unaffected"
}
]
}
],
"published": "2026-10-07T08:16:57.053",
"references": [
{
"url": "https://access.redhat.com/security/cve/CVE-2026-107121",
"source": "secalert@redhat.com"
},
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2547296",
"source": "secalert@redhat.com"
}
],
"vulnStatus": "Received",
"weaknesses": [
{
"type": "Primary",
"source": "secalert@redhat.com",
"description": [
{
"lang": "en",
"value": "CWE-319"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "A flaw was found in the SMTP email configuration handling of the keycloak-services component. When the STARTTLS option is enabled, Keycloak fails to strictly enforce an encrypted connection, allowing it to fall back to unencrypted communication if the encryption request is tampered with. An attacker who can intercept network traffic can exploit this to capture sensitive email credentials and message content in plain text."
}
],
"lastModified": "2026-10-07T08:16:57.053",
"sourceIdentifier": "secalert@redhat.com"
}