Red Hat Keycloak 26.6/26.6.6 Account Linking Endpoint improper authorization

Summaryinfo

A vulnerability categorized as critical has been discovered in Red Hat Keycloak 26.6/26.6.6. This impacts an unknown function of the component Account Linking Endpoint. Such manipulation leads to improper authorization. This vulnerability is traded as CVE-2026-15571. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in Red Hat Keycloak 26.6/26.6.6. It has been rated as critical. Affected by this issue is an unknown functionality of the component Account Linking Endpoint. 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. CVE summarizes:

A flaw was found in the legacy client-initiated account-linking endpoint of Keycloak, a widely used open-source identity and access management solution. The mechanism used to protect the account-linking process from unauthorized requests relies on a hash that can be predicted by a malicious OIDC client. By tricking a user into authenticating, an attacker-controlled client can forge a valid linking URL to connect the victim's account to an attacker's external identity. This results in a full account takeover, allowing the attacker to log in as the victim.

The advisory is available at access.redhat.com. This vulnerability is handled as CVE-2026-15571 since 07/13/2026. The exploitation is known to be easy. The attack may be launched remotely. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 08/18/2026). This vulnerability is assigned to T1548.002 by the MITRE ATT&CK project.

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

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• Red Hat

Name

• Keycloak

Version

• 26.6
• 26.6.6

License

• open-source

Website

• Vendor: https://www.redhat.com/

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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