{"cve":"CVE-2024-9666","nvd":{"published":"2024-11-25T08:15:10.943","modified":"2026-09-21T06:16:59.443","status":"Deferred","description":"A vulnerability was found in the Keycloak Server. The Keycloak Server is vulnerable to a denial of service (DoS) attack due to improper handling of proxy headers. When Keycloak is configured to accept incoming proxy headers, it may accept non-IP values, such as obfuscated identifiers, without proper validation. This issue can lead to costly DNS resolution operations, which an attacker could exploit to tie up IO threads and potentially cause a denial of service.\nThe attacker must have access to send requests to a Keycloak instance that is configured to accept proxy headers, specifically when reverse proxies do not overwrite incoming headers, and Keycloak is configured to trust these headers.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","score":4.7},"cwes":["CWE-444"],"references":["https://access.redhat.com/errata/RHSA-2024:10175","https://access.redhat.com/errata/RHSA-2024:10176","https://access.redhat.com/errata/RHSA-2024:10177","https://access.redhat.com/errata/RHSA-2024:10178","https://access.redhat.com/security/cve/CVE-2024-9666"],"products":[],"source":"nvd","synced_at":"2026-10-19T21:57:34.731061660+00:00"},"epss":{"cve":"CVE-2024-9666","score":0.00403,"percentile":0.34536,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-jgwc-jh89-rpgq","url":"https://osv.dev/vulnerability/GHSA-jgwc-jh89-rpgq","summary":"Keycloak proxy header handling Denial-of-Service (DoS) vulnerability","modified":"2026-09-10T03:50:20.939032260Z","packages":[{"ecosystem":"Maven","name":"org.keycloak:keycloak-quarkus-server","purl":"pkg:maven/org.keycloak/keycloak-quarkus-server","ranges":["all versions"],"fixed":[]},{"ecosystem":"Maven","name":"org.keycloak:keycloak-quarkus-server","purl":"pkg:maven/org.keycloak/keycloak-quarkus-server","ranges":[">=25.0.0 <26.0.6"],"fixed":["26.0.6"]}]}],"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."]}