Red Hat Keycloak Device Authorization Grant Flow improper authorization

Summaryinfo

A vulnerability, which was classified as critical, has been found in Red Hat Keycloak. The impacted element is an unknown function of the component Device Authorization Grant Flow. The manipulation leads to improper authorization. This vulnerability is traded as CVE-2026-88770. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Red Hat Keycloak (affected version unknown). This issue affects an unknown functionality of the component Device Authorization Grant Flow. 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, integrity, and availability. The summary by CVE is:

A flaw was found in the Device Authorization Grant flow of Keycloak, an identity and access management solution. The issue occurs because the token redemption process fails to check if a user account is currently locked due to brute-force protection. If an attacker has an active session for a locked account, they can complete the device login process and receive new security tokens. This allows the attacker to maintain access to the account even when it should be temporarily disabled to prevent unauthorized entry.

The advisory is shared at access.redhat.com. The identification of this vulnerability is CVE-2026-88770 since 09/10/2026. The exploitation is known to be easy. The attack may be initiated remotely. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/10/2026). MITRE ATT&CK project uses the attack technique T1548.002 for this issue.

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

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Productinfo

Vendor

• Red Hat

Name

• Keycloak

License

• open-source

Website

• Vendor: https://www.redhat.com/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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