CVE-2026-107889
Full vulnerability record from the local CVENow database.
Description
A flaw was found in the login theme rendering component of Keycloak. The issue occurs because the security filter responsible for cleaning user input can be bypassed, allowing a realm administrator to store malicious scripts in display fields. This could result in unauthorized JavaScript execution in the browsers of users visiting the login page, potentially leading to data exposure or session interference.
Severity
MEDIUM
CVSS score
5.5
(v3.1)
Vulnerability status
Awaiting Analysis
Source identifier
Published
2026-10-09 05:16:44.583000
Last modified
2026-11-06 18:17:42.870000
View original CVE JSON
{
"id": "CVE-2026-107889",
"sourceIdentifier": "[email protected]",
"published": "2026-10-09T05:16:44.583",
"lastModified": "2026-11-06T18:17:42.870",
"vulnStatus": "Awaiting Analysis",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "A flaw was found in the login theme rendering component of Keycloak. The issue occurs because the security filter responsible for cleaning user input can be bypassed, allowing a realm administrator to store malicious scripts in display fields. This could result in unauthorized JavaScript execution in the browsers of users visiting the login page, potentially leading to data exposure or session interference."
}
],
"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:L/PR:H/UI:N/S:C/C:L/I:L/A:N",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "HIGH",
"userInteraction": "NONE",
"scope": "CHANGED",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"availabilityImpact": "NONE"
},
"exploitabilityScore": 2.3,
"impactScore": 2.7
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-13T16:45:42.974434Z",
"id": "CVE-2026-107889",
"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-79"
}
]
}
],
"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-2026-107889",
"source": "[email protected]"
},
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2548355",
"source": "[email protected]"
}
]
}