CVE-2026-16093
Keycloak provides a mechanism called Client Policies to enforce security requirements on clients, such as requiring them to use signed JWTs
CVSS
5.4
Medio
EPSS
0.2%
p9
KEV
—
Exploit Today
3
0-100
Publicado: 17 jul 2026 · Última mod.: 21 jul 2026 · CWE-807
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.