Description
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.
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Remediation
No vendor fix or workaround currently provided.
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Tracking
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References
History
Fri, 17 Jul 2026 16:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | Keycloak-services: keycloak-services: required signed-jwt assertion policy can be bypassed with unsigned assertion headers | |
| First Time appeared |
Redhat
Redhat build Keycloak Redhat jboss Data Grid Redhat jbosseapxp Redhat red Hat Single Sign On |
|
| Weaknesses | CWE-807 | |
| CPEs | cpe:/a:redhat:build_keycloak: cpe:/a:redhat:jboss_data_grid:8 cpe:/a:redhat:jbosseapxp cpe:/a:redhat:red_hat_single_sign_on:7 |
|
| Vendors & Products |
Redhat
Redhat build Keycloak Redhat jboss Data Grid Redhat jbosseapxp Redhat red Hat Single Sign On |
|
| References |
| |
| Metrics |
cvssV3_1
|
Status: PUBLISHED
Assigner: redhat
Published:
Updated: 2026-07-17T16:42:52.407Z
Reserved: 2026-07-17T14:08:34.722Z
Link: CVE-2026-16093
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OpenCVE Enrichment
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Weaknesses