CVE-2026-37979

A flaw was found in Keycloak. This access control vulnerability in Keycloak's OpenID Connect (OIDC) token introspection endpoint allows a confidential client to bypass audience restrictions. An attacker-controlled client with valid credentials can retrieve sensitive token claims intended for other resource servers, compromising the confidentiality of lightweight access tokens. This issue can be exploited remotely by any confidential client in the realm with valid credentials.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://access.redhat.com/errata/RHSA-2026:19596	Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:19597	Vendor Advisory
https://access.redhat.com/security/cve/CVE-2026-37979	Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2455328	Vendor Advisory

Configurations

Configuration 1 (hide)

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

History

29 Oct 2026, 10:17

Type	Values Removed	Values Added
CWE		CWE-639

26 Oct 2026, 13:10

Type	Values Removed	Values Added
Summary		(es) Se encontró una falla en Keycloak. Esta vulnerabilidad de control de acceso en el endpoint de introspección de tokens de OpenID Connect (OIDC) de Keycloak permite a un cliente confidencial eludir las restricciones de audiencia. Un cliente controlado por un atacante con credenciales válidas puede recuperar claims de token sensibles destinados a otros servidores de recursos, comprometiendo la confidencialidad de los tokens de acceso ligeros. Este problema puede ser explotado remotamente por cualquier cliente confidencial en el realm con credenciales válidas.

Information

Published : 2026-05-19 12:16

Updated : 2026-10-29 10:17

NVD link : CVE-2026-37979

Mitre link : CVE-2026-37979

CVE.ORG link : CVE-2026-37979

JSON object : View

Products Affected

redhat

build_of_keycloak

CWE

CWE-639

Authorization Bypass Through User-Controlled Key

CWE-284

Improper Access Control

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