CVE-2026-9799

Summary

A flaw was found in org.keycloak.authorization. An authenticated user with a granted User-Managed Access (UMA) permission ticket for one resource can exploit this by using a specific permission request prefix to bypass per-resource access control. This allows the user to gain unauthorized access to all resources of that type within the same resource server, even if they do not have a ticket for those specific resources. This vulnerability requires the resource server to be configured in PERMISSIVE policy enforcement mode and affects typed resources with ownerManagedAccess enabled, where no explicit policy protects the resource type. The primary consequence is unauthorized information disclosure or modification of resources.

Affected Software

VendorProductVersion RangeStatus
Red HatRed Hat build of Keycloak 26.426.4.13-1 < *unaffected
Red HatRed Hat build of Keycloak 26.426.4-19 < *unaffected
Red HatRed Hat build of Keycloak 26.426.4-19 < *unaffected
Red HatRed Hat build of Keycloak 26.626.6.4-2 < *unaffected
Red HatRed Hat build of Keycloak 26.626.6-8 < *unaffected
Red HatRed Hat build of Keycloak 26.626.6-8 < *unaffected

Weaknesses

  • CWE-639: Authorization Bypass Through User-Controlled Key

Workarounds

To mitigate this issue, ensure that the Keycloak client's policy enforcement mode is set to ENFORCING instead of PERMISSIVE. The PERMISSIVE mode is a non-default configuration that enables the vulnerability. Changing this setting will prevent the unauthorized access to resources of the same type. Consult Keycloak documentation for specific instructions on configuring policy enforcement mode for your client. This change may require a restart or reload of the Keycloak service to take effect and could impact existing authorization policies if not carefully managed.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References