{"id":"CVE-2026-9798","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-9798","summary":"Keycloak has an Authentication Bypass by Primary Weakness","details":"A flaw was found in Keycloak, an open-source identity and access management solution. When a user account is temporarily locked due to repeated failed login attempts, an attacker with valid client credentials can exploit the Client-Initiated Backchannel Authentication (CIBA) flow to bypass this brute-force protection. This allows continued authentication attempts and token issuance even when the account should be locked, potentially enabling further unauthorized access attempts.","published":"2026-05-28T06:31:09Z","modified":"2026-08-21T22:26:53.645158503Z","cvss":{"score":4.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N"},"epss":{"score":0.00348,"percentile":0.2738,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Maven","name":"org.keycloak:keycloak-services","fixedVersion":null},{"ecosystem":"Maven","name":"org.keycloak:keycloak-services","fixedVersion":null}],"fix":{"url":"https://github.com/keycloak/keycloak/pull/49791","label":"keycloak/keycloak#49791"},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-9798"},{"type":"WEB","url":"https://github.com/keycloak/keycloak/issues/49432"},{"type":"WEB","url":"https://github.com/keycloak/keycloak/pull/49791"},{"type":"WEB","url":"https://github.com/keycloak/keycloak/pull/49903"},{"type":"WEB","url":"https://github.com/keycloak/keycloak/pull/49905"},{"type":"WEB","url":"https://github.com/keycloak/keycloak/commit/11c2695064cd93da1d333df3f69d4a4141e86c29"},{"type":"WEB","url":"https://github.com/keycloak/keycloak/commit/2edc6b112e2dedce63062b89ab3c7ae542e0d9ac"},{"type":"WEB","url":"https://github.com/keycloak/keycloak/commit/a11e3254efc16ae72ce5092b93b9f557a4ba43ae"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:50846"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:50847"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:50848"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:50849"},{"type":"WEB","url":"https://access.redhat.com/security/cve/CVE-2026-9798"},{"type":"WEB","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2482470"},{"type":"PACKAGE","url":"https://github.com/keycloak/keycloak"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-21T22:26:53.645158503Z"}}