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 v3 5.9 MEDIUM

5.9^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.2 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://access.redhat.com/errata/RHSA-2026:50846
https://access.redhat.com/errata/RHSA-2026:50847
https://access.redhat.com/errata/RHSA-2026:50848
https://access.redhat.com/errata/RHSA-2026:50849
https://access.redhat.com/security/cve/CVE-2026-9793	Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2482460	Issue Tracking Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:-:*:*:*

History

26 Oct 2026, 12:10

Type	Values Removed	Values Added
Summary		(es) Se encontró un fallo en Keycloak. Cuando se envía un objeto de solicitud cifrado con JSON Web Encryption (JWE), Keycloak puede procesar incorrectamente las reclamaciones sin firmar si el contenido descifrado es JSON en bruto, eludiendo la política de firma configurada. Esto permite a un atacante remoto enviar reclamaciones no autorizadas, lo que lleva a un compromiso de la integridad de los datos dentro del flujo de autorización de OpenID Connect (OIDC). Si bien una lista de permitidos de URI de redirección actúa como un control compensatorio, esta vulnerabilidad viola los requisitos de firma de OIDC Core y Financial-grade API (FAPI).

Information

Published : 2026-05-28 05:16

Updated : 2026-10-26 12:10

NVD link : CVE-2026-9793

Mitre link : CVE-2026-9793

CVE.ORG link : CVE-2026-9793

JSON object : View

Products Affected

redhat

build_of_keycloak

CWE

CWE-347

Improper Verification of Cryptographic Signature

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