CVE-2026-18573
Received Received - Intake

Keycloak Client Policy Bypass via Public-to-Confidential Client Update

Publication date: 2026-08-02

Last updated on: 2026-08-02

Assigner: Red Hat, Inc.

Description
A flaw was found in the keycloak-services component of Keycloak, which is used for managing authentication and authorization flows. The issue occurs when a realm administrator configures client policies to enforce specific authentication requirements on confidential clients. Due to improper evaluation of the client state during an update operation, an attacker with client management permissions can bypass these security policies by first creating a public client and then updating it to a confidential client with weaker authentication. This can result in the persistence of clients that do not comply with the intended security hardening of the realm.

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Meta Information

Published
2026-08-02
Last Modified
2026-08-02
Generated
2026-08-02
AI Q&A
2026-08-02
EPSS Evaluated
N/A
NVD
CVE-2026-18573
EUVD
EUVD-2026-51927

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
redhat keycloak *

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-862 The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

Attack-Flow Graph

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Executive Summary

This vulnerability is in Keycloak's client policy enforcement. A realm admin sets rules for confidential clients' authentication. An attacker with client management rights creates a public client, then changes it to confidential with weaker auth, bypassing security policies.

Detection Guidance

To detect this vulnerability, review Keycloak client configurations for unauthorized changes from public to confidential clients. Check logs for client update operations performed by non-admin users. Inspect realm client policies for inconsistencies in enforced authentication requirements.

Impact Analysis

If exploited, attackers could bypass enforced authentication policies, allowing unauthorized access to systems relying on Keycloak for security. This may lead to data breaches or unauthorized actions within protected applications.

Compliance Impact

This flaw could undermine compliance by allowing unauthorized access to sensitive data, violating confidentiality requirements in GDPR and HIPAA. Organizations using Keycloak may fail audits if client policies are bypassed.

Mitigation Strategies

Review client configurations in Keycloak to ensure no public clients were improperly updated to confidential clients with weaker authentication. Remove or correct any non-compliant clients. Restrict client management permissions to trusted administrators only.

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