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.
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions |
|---|---|---|---|
| Red Hat | Red Hat Build of Keycloak | affected | — |
| Red Hat | Red Hat Build of Keycloak | affected | — |
| Red Hat | Red Hat Build of Keycloak | affected | — |
| Red Hat | Red Hat Data Grid 8 | affected | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | affected | — |
| Red Hat | Red Hat Single Sign-On 7 | affected | — |
No data.
No data.
No data available yet.
Remediation
No remediation available yet.
Tracking
Sign in to view the affected projects.
Advisories
No advisories yet.
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
|
MITRE
Status: PUBLISHED
Assigner: redhat
Published:
Updated: 2026-07-17T16:42:52.407Z
Reserved: 2026-07-17T14:08:34.722Z
Link: CVE-2026-16093
Vulnrichment
No data.
NVD
No data.
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
-
CWE-807
Reliance on Untrusted Inputs in a Security Decision