CVE-2026-9793
A flaw was found in Keycloak. When a JSON Web Encryption (JWE) encrypted request object is submitted, Keycloak may incorrectly process unsigned claims if the decrypted content is raw JSON, bypassing the configured signature policy. This allows a remote attacker to submit unauthorized claims, leading to a compromise of data integrity within the OpenID Connect (OIDC) authorization flow. While a redirect URI allowlist acts as a compensating control, this vulnerability violates OIDC Core and Financial-grade API (FAPI) signing requirements.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- Puntuación base: 7.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.26%
- Percentil entre todas las CVEs puntuadas: 16
- Fecha de la puntuación: 5/10/2026
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
T1190Exploit Public-Facing Applicationinitial access85 % - Impacto principal
T1565.002Transmitted Data Manipulationimpact80 %
Vulnerabilidad en procesamiento de JWE en Keycloak expuesta en red sin autenticación (AV:N, PR:N, UI:N). Permite inyectar claims no firmados, comprometiendo integridad de datos en flujo OIDC (I:H).
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)
CWE
- CWE-347
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-9793",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-9793",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-05-30T01:52:59.517905Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "secalert@redhat.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 5.9,
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "HIGH",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 2.2
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.5,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "secalert@redhat.com",
"affectedData": [
{
"cpes": [
"cpe:/a:redhat:build_keycloak:26.4::el9"
],
"vendor": "Red Hat",
"product": "Red Hat build of Keycloak 26.4",
"versions": [
{
"status": "unaffected",
"version": "26.4.14-1",
"lessThan": "*",
"versionType": "rpm"
}
],
"packageName": "rhbk/keycloak-operator-bundle",
"collectionURL": "https://catalog.redhat.com/software/containers/",
"defaultStatus": "affected"
},
{
"cpes": [
"cpe:/a:redhat:build_keycloak:26.4::el9"
],
"vendor": "Red Hat",
"product": "Red Hat build of Keycloak 26.4",
"versions": [
{
"status": "unaffected",
"version": "26.4-22",
"lessThan": "*",
"versionType": "rpm"
}
],
"packageName": "rhbk/keycloak-rhel9",
"collectionURL": "https://catalog.redhat.com/software/containers/",
"defaultStatus": "affected"
},
{
"cpes": [
"cpe:/a:redhat:build_keycloak:26.4::el9"
],
"vendor": "Red Hat",
"product": "Red Hat build of Keycloak 26.4",
"versions": [
{
"status": "unaffected",
"version": "26.4-22",
"lessThan": "*",
"versionType": "rpm"
}
],
"packageName": "rhbk/keycloak-rhel9-operator",
"collectionURL": "https://catalog.redhat.com/software/containers/",
"defaultStatus": "affected"
},
{
"cpes": [
"cpe:/a:redhat:build_keycloak:26.4::el9"
],
"vendor": "Red Hat",
"product": "Red Hat build of Keycloak 26.4.14",
"packageName": "rhbk/keycloak-rhel9",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "unaffected"
},
{
"cpes": [
"cpe:/a:redhat:build_keycloak:26.6::el9"
],
"vendor": "Red Hat",
"product": "Red Hat build of Keycloak 26.6",
"versions": [
{
"status": "unaffected",
"version": "26.6.5-1",
"lessThan": "*",
"versionType": "rpm"
}
],
"packageName": "rhbk/keycloak-operator-bundle",
"collectionURL": "https://catalog.redhat.com/software/containers/",
"defaultStatus": "affected"
},
{
"cpes": [
"cpe:/a:redhat:build_keycloak:26.6::el9"
],
"vendor": "Red Hat",
"product": "Red Hat build of Keycloak 26.6",
"versions": [
{
"status": "unaffected",
"version": "26.6-11",
"lessThan": "*",
"versionType": "rpm"
}
],
"packageName": "rhbk/keycloak-rhel9",
"collectionURL": "https://catalog.redhat.com/software/containers/",
"defaultStatus": "affected"
},
{
"cpes": [
"cpe:/a:redhat:build_keycloak:26.6::el9"
],
"vendor": "Red Hat",
"product": "Red Hat build of Keycloak 26.6",
"versions": [
{
"status": "unaffected",
"version": "26.6-11",
"lessThan": "*",
"versionType": "rpm"
}
],
"packageName": "rhbk/keycloak-rhel9-operator",
"collectionURL": "https://catalog.redhat.com/software/containers/",
"defaultStatus": "affected"
},
{
"cpes": [
"cpe:/a:redhat:build_keycloak:26.6::el9"
],
"vendor": "Red Hat",
"product": "Red Hat build of Keycloak 26.6.5",
"collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
"defaultStatus": "unaffected"
}
]
}
],
"published": "2026-05-28T05:16:40.697",
"references": [
{
"url": "https://access.redhat.com/errata/RHSA-2026:50846",
"source": "secalert@redhat.com"
},
{
"url": "https://access.redhat.com/errata/RHSA-2026:50847",
"source": "secalert@redhat.com"
},
{
"url": "https://access.redhat.com/errata/RHSA-2026:50848",
"source": "secalert@redhat.com"
},
{
"url": "https://access.redhat.com/errata/RHSA-2026:50849",
"source": "secalert@redhat.com"
},
{
"url": "https://access.redhat.com/security/cve/CVE-2026-9793",
"tags": [
"Vendor Advisory"
],
"source": "secalert@redhat.com"
},
{
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2482460",
"tags": [
"Issue Tracking",
"Vendor Advisory"
],
"source": "secalert@redhat.com"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Secondary",
"source": "secalert@redhat.com",
"description": [
{
"lang": "en",
"value": "CWE-347"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "A flaw was found in Keycloak. When a JSON Web Encryption (JWE) encrypted request object is submitted, Keycloak may incorrectly process unsigned claims if the decrypted content is raw JSON, bypassing the configured signature policy. This allows a remote attacker to submit unauthorized claims, leading to a compromise of data integrity within the OpenID Connect (OIDC) authorization flow. While a redirect URI allowlist acts as a compensating control, this vulnerability violates OIDC Core and Financial-grade API (FAPI) signing requirements."
}
],
"lastModified": "2026-08-20T01:16:54.610",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:-:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E5C930CB-4EAD-497B-A44B-D880F2A1F85B"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "secalert@redhat.com"
}