CVE-2026-37979 MEDIUM

CVE-2026-37979: Keycloak: keycloak: information disclosure via oidc token introspection endpoint audience bypass

Vendor Red Hat
Product Red Hat build of Keycloak 26.4.12
Published May 19, 2026
Last update May 20, 2026

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

May 19, 2026 CVE published
May 20, 2026 Record updated