{"cve":"CVE-2026-9798","nvd":{"published":"2026-05-28T06:16:29.330","modified":"2026-10-26T12:10:00.130","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N","score":4.3},"cwes":["CWE-305"],"references":["https://access.redhat.com/errata/RHSA-2026:50846","https://access.redhat.com/errata/RHSA-2026:50847","https://access.redhat.com/errata/RHSA-2026:50848","https://access.redhat.com/errata/RHSA-2026:50849","https://access.redhat.com/security/cve/CVE-2026-9798"],"products":["redhat:build_of_keycloak"],"source":"nvd","synced_at":"2026-10-26T12:35:18.182177120+00:00"},"epss":{"cve":"CVE-2026-9798","score":0.00375,"percentile":0.31218,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-q6h7-xxp7-7429","url":"https://osv.dev/vulnerability/GHSA-q6h7-xxp7-7429","summary":"Keycloak has an Authentication Bypass by Primary Weakness","modified":"2026-09-10T03:51:06.866862420Z","packages":[{"ecosystem":"Maven","name":"org.keycloak:keycloak-services","purl":"pkg:maven/org.keycloak/keycloak-services","ranges":["<=26.4.7"],"fixed":[]},{"ecosystem":"Maven","name":"org.keycloak:keycloak-services","purl":"pkg:maven/org.keycloak/keycloak-services","ranges":[">=26.5.0 <=26.6.4"],"fixed":[]}]}],"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."]}