{"id":"CVE-2026-97174","title":"Keycloak-services: keycloak-services: ciba sub parameter injection causes attacker authentication to issue victim tokens","summary":"A flaw was found in the Client-Initiated Backchannel Authentication (CIBA) implementation of Keycloak. The CIBA endpoint fails to properly validate the sub parameter, allowing it to be stored as an additional request parameter. During th…","severity":"medium","cvss":6.8,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N","cvssSource":"cna","cwe":["CWE-20"],"vendor":"Red Hat","product":"keycloak-services","affected":["keycloak-services (all versions)","rhbk/keycloak-rhel9 (all versions)","keycloak-services"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-11-05T20:58:27.807112Z"},"published":"2026-11-05","updated":"2026-11-05","sourceUpdated":"2026-11-05T20:58:34.387Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-97174","references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-97174"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2539961","label":"RHBZ#2539961"}],"tags":["cve.org"],"ingestedAt":"2026-11-05T22:38:31.937Z","slug":"CVE-2026-97174","body":"## Overview\n\nA flaw was found in the Client-Initiated Backchannel Authentication (CIBA) implementation of Keycloak. The CIBA endpoint fails to properly validate the sub parameter, allowing it to be stored as an additional request parameter. During the token issuance process, this injected value overwrites the legitimate subject identifier. This allows an attacker to authenticate as themselves but receive security tokens belonging to a different victim user, leading to unauthorized account access.\n\n## Affected\n\n- `keycloak-services (all versions)`\n- `rhbk/keycloak-rhel9 (all versions)`\n- `keycloak-services`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n### Workarounds\n\nMitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.","depth":"sunlit","depthScore":37,"depthScoreParts":{"impact":37.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}