A flaw was found in Keycloak. An improper Access Control vulnerability in Keycloak’s User-Managed Access (UMA) resource_set endpoint allows attackers with valid credentials to bypass the allowRemoteResourceManagement=false restriction. This occurs due to incomplete enforcement of access control checks on PUT operations to the resource_set endpoint. This issue enables unauthorized modification of protected resources, impacting data integrity.
https://github.com/muff1nmigi/keycloak-security-research
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-14389
https://bugzilla.redhat.com/show_bug.cgi?id=2450240