{"cve":"CVE-2026-4874","nvd":{"published":"2026-03-26T08:16:22.700","modified":"2026-06-26T08:16:23.963","status":"Modified","description":"A flaw was found in Keycloak. An authenticated attacker can perform Server-Side Request Forgery (SSRF) by manipulating the `client_session_host` parameter during refresh token requests. This occurs when a Keycloak client is configured to use the `backchannel.logout.url` with the `application.session.host` placeholder. Successful exploitation allows the attacker to make HTTP requests from the Keycloak server’s network context, potentially probing internal networks or internal APIs, leading to information disclosure.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N","score":3.1},"cwes":["CWE-918"],"references":["https://access.redhat.com/errata/RHSA-2026:25097","https://access.redhat.com/errata/RHSA-2026:25098","https://access.redhat.com/errata/RHSA-2026:30049","https://access.redhat.com/errata/RHSA-2026:30050","https://access.redhat.com/security/cve/CVE-2026-4874"],"products":["redhat:build_of_keycloak","redhat:jboss_enterprise_application_platform","redhat:jboss_enterprise_application_platform_expansion_pack","redhat:single_sign-on"],"source":"nvd","synced_at":"2026-10-19T22:28:18.033120106+00:00"},"epss":{"cve":"CVE-2026-4874","score":0.00353,"percentile":0.29047,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-22rm-wp4x-v5cx","url":"https://osv.dev/vulnerability/GHSA-22rm-wp4x-v5cx","summary":"Keycloak Server-Side Request Forgery via OIDC token endpoint manipulation","modified":"2026-09-10T03:50:36.368445797Z","packages":[{"ecosystem":"Maven","name":"org.keycloak:keycloak-services","purl":"pkg:maven/org.keycloak/keycloak-services","ranges":[">=26.5.0 <26.6.3"],"fixed":["26.6.3"]},{"ecosystem":"Maven","name":"org.keycloak:keycloak-services","purl":"pkg:maven/org.keycloak/keycloak-services","ranges":["<26.4.13"],"fixed":["26.4.13"]}]}],"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."]}