Keycloak OIDC Introspection Audience Bypass Vulnerability
CVE-2026-37979 Published on May 19, 2026
Keycloak: keycloak: information disclosure via oidc token introspection endpoint audience bypass
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.
Vulnerability Analysis
CVE-2026-37979 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality, with no impact on integrity and availability.
Timeline
Reported to Red Hat.
Made public. 43 days later.
Weakness Type
What is an Authorization Vulnerability?
The software does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
CVE-2026-37979 has been classified to as an Authorization vulnerability or weakness.
Products Associated with CVE-2026-37979
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