{"cve":"CVE-2026-37979","nvd":{"published":"2026-05-19T12:16:18.330","modified":"2026-10-26T13:10:00.140","status":"Analyzed","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","score":6.5},"cwes":["CWE-284"],"references":["https://access.redhat.com/errata/RHSA-2026:19596","https://access.redhat.com/errata/RHSA-2026:19597","https://access.redhat.com/security/cve/CVE-2026-37979","https://bugzilla.redhat.com/show_bug.cgi?id=2455328"],"products":["redhat:build_of_keycloak"],"source":"nvd","synced_at":"2026-10-26T13:39:24.642594360+00:00"},"epss":{"cve":"CVE-2026-37979","score":0.00366,"percentile":0.30168,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-4x37-hw65-52w8","url":"https://osv.dev/vulnerability/GHSA-4x37-hw65-52w8","summary":"Keycloak: Information disclosure via OIDC token introspection endpoint audience bypass","modified":"2026-08-26T01:11:44.714991321Z","packages":[{"ecosystem":"Maven","name":"org.keycloak:keycloak-services","purl":"pkg:maven/org.keycloak/keycloak-services","ranges":["<26.6.2"],"fixed":["26.6.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}