# CVE-2026-16093

## Summary

- **CVE ID:** CVE-2026-16093
- **Severity:** MEDIUM
- **CVSS Score:** 5.4 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N)
- **CWE:** CWE-807
- **Published:** Jul 17, 2026
- **Last Modified:** Aug 31, 2026

## 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.

## Affected Products

No affected products listed.

## References

- [CNA](https://access.redhat.com/security/cve/CVE-2026-16093)
- [CNA](https://bugzilla.redhat.com/show_bug.cgi?id=2501729)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.30%
- **EPSS Percentile:** 22.8

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._