Red Hat Keycloak JWT Authorization Grant Processing improper authorization

Summaryinfo

A vulnerability identified as problematic has been detected in Red Hat Keycloak. The affected element is an unknown function of the component JWT Authorization Grant Processing. The manipulation leads to improper authorization. This vulnerability is documented as CVE-2026-1609. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Red Hat Keycloak (affected version not known). This issue affects some unknown functionality of the component JWT Authorization Grant Processing. The manipulation with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality. The summary by CVE is:

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.

It is possible to read the advisory at access.redhat.com. The identification of this vulnerability is CVE-2026-1609 since 01/29/2026. The exploitation is known to be easy. The attack may be initiated remotely. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 07/16/2026). The attack technique deployed by this issue is T1548.002 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-44841). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

• Red Hat

Name

• Keycloak

License

• open-source

Website

• Vendor: https://www.redhat.com/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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