CVE-2026-107121
Full vulnerability record from the local CVENow database.
Description
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.
Severity
MEDIUM
CVSS score
6.5
(v3.1)
Vulnerability status
Awaiting Analysis
Source identifier
Published
2026-10-07 08:16:57.053000
Last modified
2026-11-06 18:17:41.900000
View original CVE JSON
{
"id": "CVE-2026-107121",
"sourceIdentifier": "[email protected]",
"published": "2026-10-07T08:16:57.053",
"lastModified": "2026-11-06T18:17:41.900",
"vulnStatus": "Awaiting Analysis",
"cveTags": [],
"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."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "Red Hat",
"product": "Red Hat build of Keycloak 26.6",
"defaultStatus": "affected",
"collectionURL": "https://catalog.redhat.com/software/containers/",
"packageName": "rhbk/keycloak-operator-bundle",
"cpes": [
"cpe:/a:redhat:build_keycloak:26.6::el9"
],
"versions": [
{
"version": "26.6.8-2",
"lessThan": "*",
"versionType": "rpm",
"status": "unaffected"
}
]
},
{
"vendor": "Red Hat",
"product": "Red Hat build of Keycloak 26.6",
"defaultStatus": "affected",
"collectionURL": "https://catalog.redhat.com/software/containers/",
"packageName": "rhbk/keycloak-rhel9",
"cpes": [
"cpe:/a:redhat:build_keycloak:26.6::el9"
],
"versions": [
{
"version": "26.6-24",
"lessThan": "*",
"versionType": "rpm",
"status": "unaffected"
}
]
},
{
"vendor": "Red Hat",
"product": "Red Hat build of Keycloak 26.6",
"defaultStatus": "affected",
"collectionURL": "https://catalog.redhat.com/software/containers/",
"packageName": "rhbk/keycloak-rhel9-operator",
"cpes": [
"cpe:/a:redhat:build_keycloak:26.6::el9"
],
"versions": [
{
"version": "26.6-24",
"lessThan": "*",
"versionType": "rpm",
"status": "unaffected"
}
]
},
{
"vendor": "Red Hat",
"product": "Red Hat build of Keycloak 26.6.8",
"defaultStatus": "unaffected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "keycloak-services",
"cpes": [
"cpe:/a:redhat:build_keycloak:26.6::el9"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat build of Keycloak 26.6.8",
"defaultStatus": "unaffected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "rhbk/keycloak-rhel9",
"cpes": [
"cpe:/a:redhat:build_keycloak:26.6::el9"
]
},
{
"vendor": "Red Hat",
"product": "Red Hat Single Sign-On 7",
"defaultStatus": "unaffected",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"packageName": "keycloak-services",
"cpes": [
"cpe:/a:redhat:red_hat_single_sign_on:7"
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N",
"baseScore": 6.5,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "HIGH",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "LOW",
"availabilityImpact": "NONE"
},
"exploitabilityScore": 2.2,
"impactScore": 4.2
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-07T15:56:53.243244Z",
"id": "CVE-2026-107121",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-319"
}
]
}
],
"references": [
{
"url": "https://access.redhat.com/errata/RHSA-2026:95761",
"source": "[email protected]"
},
{
"url": "https://access.redhat.com/errata/RHSA-2026:95762",
"source": "[email protected]"
},
{
"url": "https://access.redhat.com/security/cve/CVE-2026-107121",
"source": "[email protected]"
},
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2547296",
"source": "[email protected]"
}
]
}