CVE-2026-16093 - Keycloak-services: keycloak-services: required signed-jwt assertion policy can be bypassed with unsigned assertion headers
CVE ID :CVE-2026-16093
Published : July 17, 2026, 4:42 p.m. | 5 minutes ago
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.
Severity: 5.4 | MEDIUM
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Published : July 17, 2026, 4:42 p.m. | 5 minutes ago
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.
Severity: 5.4 | MEDIUM
Visit the link for more details, such as CVSS details, affected products, timeline, and more...