CVE-2026-9801
Full vulnerability record from the local CVENow database.
Description
A flaw was found in Keycloak. A remote attacker with high privileges, such as a realm administrator configuring a malicious Lightweight Directory Access Protocol (LDAP) server or an attacker compromising an upstream LDAP server, could exploit this vulnerability. By sending a malformed LDAP password policy response during a password authentication request, the attacker can trigger an OutOfMemoryError. This causes the Keycloak Java Virtual Machine (JVM) to terminate, leading to a denial of service (DoS) for all realms on the affected node.
Severity
MEDIUM
CVSS score
4.9
(v3.1)
Vulnerability status
Modified
Source identifier
Published
2026-05-28 06:16:29.493000
Last modified
2026-10-26 12:10:00.130000
View original CVE JSON
{
"id": "CVE-2026-9801",
"sourceIdentifier": "[email protected]",
"published": "2026-05-28T06:16:29.493",
"lastModified": "2026-10-26T12:10:00.130",
"vulnStatus": "Modified",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "A flaw was found in Keycloak. A remote attacker with high privileges, such as a realm administrator configuring a malicious Lightweight Directory Access Protocol (LDAP) server or an attacker compromising an upstream LDAP server, could exploit this vulnerability. By sending a malformed LDAP password policy response during a password authentication request, the attacker can trigger an OutOfMemoryError. This causes the Keycloak Java Virtual Machine (JVM) to terminate, leading to a denial of service (DoS) for all realms on the affected node."
},
{
"lang": "es",
"value": "Se encontró un fallo en Keycloak. Un atacante remoto con altos privilegios, como un administrador de reino configurando un servidor malicioso de Lightweight Directory Access Protocol (LDAP) o un atacante comprometiendo un servidor LDAP ascendente, podría explotar esta vulnerabilidad. Al enviar una respuesta malformada de política de contraseñas LDAP durante una solicitud de autenticación de contraseña, el atacante puede desencadenar un OutOfMemoryError. Esto provoca que la Máquina Virtual Java (JVM) de Keycloak termine, lo que lleva a una denegación de servicio (DoS) para todos los reinos en el nodo afectado."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "Red Hat",
"product": "Red Hat build of Keycloak 26.4",
"defaultStatus": "affected",
"collectionURL": "https://catalog.redhat.com/software/containers/",
"packageName": "rhbk/keycloak-operator-bundle",
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},
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"cpes": [
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{
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],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H",
"baseScore": 4.9,
"baseSeverity": "MEDIUM",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "HIGH",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.2,
"impactScore": 3.6
}
],
"ssvcV203": [
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"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-05-30T01:53:56.832854Z",
"id": "CVE-2026-9801",
"options": [
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{
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}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
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},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-1284"
}
]
}
],
"configurations": [
{
"nodes": [
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"negate": false,
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"references": [
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"url": "https://access.redhat.com/errata/RHSA-2026:25097",
"source": "[email protected]"
},
{
"url": "https://access.redhat.com/errata/RHSA-2026:25098",
"source": "[email protected]"
},
{
"url": "https://access.redhat.com/errata/RHSA-2026:30049",
"source": "[email protected]"
},
{
"url": "https://access.redhat.com/errata/RHSA-2026:30050",
"source": "[email protected]"
},
{
"url": "https://access.redhat.com/security/cve/CVE-2026-9801",
"source": "[email protected]",
"tags": [
"Mitigation",
"Vendor Advisory"
]
},
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2482473",
"source": "[email protected]",
"tags": [
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"Vendor Advisory"
]
}
]
}