{"id":"CVE-2026-18208","title":"A flaw was found in the OIDC token introspection endpoint of the keycloak-services component","summary":"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 con…","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","cwe":["CWE-862"],"vendor":"redhat","product":"build_of_keycloak","affected":["build_of_keycloak"],"published":"2026-07-31","updated":"2026-08-07","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-18208","references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-18208","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2508304","label":"secalert@redhat.com"}],"tags":["nvd"],"epss":0.00201,"epssPercentile":0.10309,"ingestedAt":"2026-08-08T14:22:57.398Z","slug":"CVE-2026-18208","body":"## Overview\n\nA 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.\n\n## Affected\n\n- `build_of_keycloak`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}