CVE-2026-16093
MEDIUM
5.4
CVSS 3.1
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.
Metadata
Severity & Metrics
5.4
MEDIUM CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Affected products (6)
| Vendor | Product | Platform | Versions |
|---|---|---|---|
| Red Hat | Red Hat Build of Keycloak | — | — |
| Red Hat | Red Hat Build of Keycloak | — | — |
| Red Hat | Red Hat Build of Keycloak | — | — |
| Red Hat | Red Hat Data Grid 8 | — | — |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | — | — |
| Red Hat | Red Hat Single Sign-On 7 | — | — |
Weakness (CWE)
| CWE | Source | Description |
|---|---|---|
| CWE-807 | cna | Reliance on Untrusted Inputs in a Security Decision |
CVSS scores (1)
| Score | Severity | Version | Source | Vector |
|---|---|---|---|---|
| 5.4 | MEDIUM | 3.1 | cna | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
References (2)