CVE-2026-16093
A flaw was discovered where this enforcement can be bypassed.
Does this matter?
Lower severity and a low EPSS score (0.30%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
- EPSS
- 0.30% probability · 23th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-807
- Affected
- redhat/build of keycloak · redhat/data grid · redhat/jboss enterprise application platform expansion pack · redhat/single sign-on
- Source
- secalert@redhat.com
References
- https://access.redhat.com/security/cve/CVE-2026-16093Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2501729Issue Tracking, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.