{"id":"BIT-keycloak-2026-16093","summary":"Keycloak-services: keycloak-services: required signed-jwt assertion policy can be bypassed with unsigned assertion headers","details":"Keycloak provides a mechanism called Client Policies to enforce security requirements on clients, such as requiring them to use signed JWTs for authentication. A flaw was discovered where this enforcement can be bypassed. An attacker with valid client credentials can provide a fake, unsigned assertion header that tricks the system into thinking the policy requirements have been met. This allows the attacker to authenticate using simpler methods like a client secret even when the administrator has mandated more secure, signed assertions.","aliases":["CVE-2026-16093"],"modified":"2026-09-17T14:45:07.164880761Z","published":"2026-08-31T14:36:55.423Z","database_specific":{"severity":"Medium","cpes":["cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:-:*:*:*","cpe:2.3:a:keycloak:keycloak:*:*:*:*:*:*:*:*"]},"references":[{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-16093"},{"type":"ADVISORY","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2501729"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-16093"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:68277"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:68278"}],"affected":[{"package":{"name":"keycloak","ecosystem":"Bitnami","purl":"pkg:bitnami/keycloak"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"26.7.3"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/keycloak/BIT-keycloak-2026-16093.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N"}]}],"schema_version":"1.9.0"}