CVE-2026-18208 — Keycloak-services: keycloak-services: inactive out-of-audience token introspection leaks signed jwt claim
A flaw was found in the OIDC token introspection endpoint of the keycloak-services component. Keycloak is an open-source identity and access management solution used to secure m…
Published: 2026-07-31 · CVSS: 6.5 · CVSS 3.1
A flaw was found in the OIDC token introspection endpoint of the keycloak-services component. Keycloak is an open-source identity and access management solution used to secure modern applications and services. The issue occurs when a confidential client, configured to receive signed JWT introspection responses, attempts to introspect a token issued for a different audience. Although the endpoint correctly identifies the token as inactive for that client, it still returns the full set of token claims within a signed JWT field. This allows an unauthorized client to bypass audience-based restrictions and access sensitive information contained in the token.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7