CVE-2026-16093
Keycloak-services: keycloak-services: required signed-jwt assertion policy can be bypassed with unsigned assertion headers
CVSS Score
5.4
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-807 |
| Vendor | red hat |
| Product | red hat build of keycloak |
| Published | Jul 17, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None
Affected Versions
Red Hat / Red Hat Build of Keycloak
All versions affected Red Hat / Red Hat Build of Keycloak
All versions affected Red Hat / Red Hat Build of Keycloak
All versions affected Red Hat / Red Hat Data Grid 8
All versions affected Red Hat / Red Hat JBoss Enterprise Application Platform Expansion Pack
All versions affected Red Hat / Red Hat Single Sign-On 7
All versions affected References
Credits
Red Hat would like to thank Paul Bottinelli (Trail of Bits) for reporting this issue.