CVE-2026-16093: Keycloak-services: required signed-jwt assertion policy can be bypassed with unsigned assertion headers
Red Hat · Red Hat build of Keycloak 26.6
Vendor fix available · Affected: Red Hat build of Keycloak 26.6 · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 34% of scored CVEs
DescriptionCVE.org
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.
Affected products9
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- Red Hat · Red Hat build of Keycloak 26.6Versions not stated
- Red Hat · Red Hat build of Keycloak 26.6Versions not stated
- Red Hat · Red Hat build of Keycloak 26.6Versions not stated
- Red Hat · Red Hat build of Keycloak 26.6.7Versions not stated
- Red Hat · Red Hat build of Keycloak 26.6.7Versions not stated
- Red Hat · Red Hat build of Keycloak 26.6.7Versions not stated
- Red Hat · Red Hat Data Grid 8Versions not stated
- Red Hat · Red Hat JBoss Enterprise Application Platform Expansion PackVersions not stated
- Red Hat · Red Hat Single Sign-On 7Versions not stated
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CoverageNo articles yet
No CyberSIXT article names CVE-2026-16093 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.