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.
CVE-2026-37979
CVSS base score
6.5 (v3.1)
Severity
MEDIUM
Attack vector
Network
Weakness
CWE-639, CWE-284
Last modified
October 29, 2026
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Affected products
redhat build of keycloak
References
- access.redhat.com Vendor Advisory
- access.redhat.com Vendor Advisory
- access.redhat.com Vendor Advisory
- bugzilla.redhat.com Vendor Advisory