CVE-2026-1609

Analyzed Analyzed - Analysis Complete

Keycloak JWT Authorization Grant Improper Access Control

Publication date: 2026-07-16

Last updated on: 2026-08-09

Assigner: redhat-SADP

Description

A flaw was found in Keycloak. When the JSON Web Token (JWT) authorization grant preview feature is enabled and a user account is disabled, Keycloak fails to validate the user’s disabled status during JWT authorization grant processing. A remote attacker with low privileges can exploit this improper access control vulnerability by presenting a valid assertion token from an external identity provider to obtain a JWT for a disabled user. This allows unauthorized access to sensitive resources.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-07-16

Last Modified

2026-08-09

Generated

2026-08-25

AI Q&A

2026-07-16

EPSS Evaluated

2026-08-24

NVD

CVE-2026-1609

EUVD

EUVD-2026-44841

Affected Vendors & Products

Vendor	Product	Version / Range
redhat	build_of_keycloak	26.5.2

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-284	The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

Attack-Flow Graph

Executive Summary

CVE-2026-1609 is an improper access control flaw in Keycloak where disabled users can still obtain JWT tokens via the JWT Authorization Grant feature. When this feature is enabled and a user account is disabled, Keycloak fails to check the disabled status during token processing. An attacker with low privileges can exploit this by using a valid assertion token from an external identity provider to get a JWT for a disabled user, gaining unauthorized access to sensitive resources.

Detection Guidance

To detect this vulnerability, check if Keycloak is running version 26.5 or later and if the JWT Authorization Grant feature is enabled. Inspect Keycloak logs for disabled user token requests or unusual JWT generation patterns. Verify if disabled users have active tokens by querying the Keycloak admin API for user sessions.

Impact Analysis

This vulnerability allows unauthorized access to sensitive resources even when user accounts are disabled. Attackers could exploit it to gain access to protected endpoints, potentially leading to data breaches, unauthorized actions, or further compromise of the system. The impact is higher if the JWT Authorization Grant feature is enabled in Keycloak.

Compliance Impact

This vulnerability could lead to unauthorized access to personal or sensitive data, violating compliance requirements under GDPR and HIPAA. GDPR mandates strict access controls and user rights management, while HIPAA requires safeguards to protect health information. Exploitation of this flaw may result in non-compliance, legal penalties, and reputational damage.

Mitigation Strategies

Upgrade Keycloak to version 26.5.3 or later immediately. Disable the JWT Authorization Grant feature if not required. Review and revoke tokens for disabled users. Monitor logs for suspicious activity and restrict access to sensitive resources until the issue is resolved.

Hi! I’m here to help you understand CVE-2026-1609. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70