Red Hat Keycloak keycloak-services improper authorization

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Red Hat Keycloak. Affected is an unknown function of the component keycloak-services. The manipulation leads to improper authorization. This vulnerability is listed as CVE-2026-18208. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in Red Hat Keycloak (affected version unknown) and classified as problematic. This issue affects an unknown functionality of the component keycloak-services. 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 the OIDC token introspection endpoint of the keycloak-services component. Keycloak is an open-source identity and access management solution used to secure modern applications and services. The issue occurs when a confidential client, configured to receive signed JWT introspection responses, attempts to introspect a token issued for a different audience. Although the endpoint correctly identifies the token as inactive for that client, it still returns the full set of token claims within a signed JWT field. This allows an unauthorized client to bypass audience-based restrictions and access sensitive information contained in the token.

It is possible to read the advisory at access.redhat.com. The identification of this vulnerability is CVE-2026-18208 since 07/29/2026. 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 07/31/2026). 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.

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Productinfo

Vendor

• Red Hat

Name

• Keycloak

License

• open-source

Website

• Vendor: https://www.redhat.com/

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