VULNERABILITY INTELLIGENCE

CVE-2026-16093

CVSS score5.4 MEDIUM
EPSS probability0.39%
CISA KEVNot currently listed
Published2026-07-17
Last modified2026-09-16
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

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.

Weakness classification

  • secalert@redhat.com: CWE-807

Primary references