CVE-2026-9799: Keycloak: keycloak: unauthorized access to resources via uma permission ticket bypass

Severity: medium (CVSS 4.6 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-25 · updated 2026-07-01
Weakness: CWE-639

Description

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 products

Red Hat build of Keycloak 26.4: from 26.4 before 26.4.13; from 26.6 before 26.6.4 — fixed in 26.4.13, 26.6.4

How to fix

Upgrade to a fixed version: Red Hat build of Keycloak 26.4 26.4.13, 26.6.4. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-9799 or the next vulnerability affects your stack