{"id":"CVE-2023-6563","aliases":["GHSA-54f3-c6hg-865h"],"url":"https://o3.security/vulnerability/CVE-2023-6563","summary":"Keycloak: offline session token dos","details":"An unconstrained memory consumption vulnerability was discovered in Keycloak. It can be triggered in environments which have millions of offline tokens (> 500,000 users with each having at least 2 saved sessions). If an attacker creates two or more user sessions and then open the \"consents\" tab of the admin User Interface, the UI attempts to load a huge number of offline client sessions leading to excessive memory and CPU consumption which could potentially crash the entire system.","published":"2023-12-14T18:01:26.005Z","modified":"2026-08-12T03:51:40.164991959Z","cvss":{"score":7.7,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H"},"epss":{"score":0.01239,"percentile":0.66372,"asOf":"2026-08-23"},"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"Maven","name":"org.keycloak:keycloak-model-jpa","fixedVersion":"21.0.0"}],"fix":null,"references":[{"type":"WEB","url":"https://access.redhat.com/downloads/content/package-browser/"},{"type":"WEB","url":"https://access.redhat.com/jbossnetwork/restricted/listSoftware.html"},{"type":"WEB","url":"https://catalog.redhat.com/software/containers/"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2023:7854"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2023:7855"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2023:7856"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2023:7857"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2023:7858"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2023-6563"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/6xxx/CVE-2023-6563.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-6563"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2253308"},{"type":"REPORT","url":"https://github.com/keycloak/keycloak/issues/13340"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:40.164991959Z"}}