---
id: "CVE-2026-4628"
kind: "vulnerability"
aliases: ["CVE-2026-4628", "GHSA-4pgc-gfrr-wcmg"]
title: "Keycloak has Improper Access Control that allows attackers with valid credentials to bypass the allowRemoteResourceManagement=false"
severity: "medium"
cvss: 4.300000190734863
epss: 0.002749999985098839
exploited: false
status: "open"
category: "runtime"
products: [{"name": "org.keycloak:keycloak-services", "fixed": [], "affected": "<= 26.6.0", "ecosystem": "maven"}, {"name": "redhat build of keycloak", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["maven", "vendor"]
tags: ["cwe-284", "java", "keycloak", "runtime", "self-hosted", "uma"]
not_affected_if: ["remote-resource-management-not-restricted", "uma-not-used"]
published_at: "2026-03-23T09:16:26+00:00"
first_seen_at: "2026-10-23T19:11:31+00:00"
updated_at: "2026-10-23T23:44:52+00:00"
sources: [{"source": "ghsa", "url": "https://github.com/advisories/GHSA-4pgc-gfrr-wcmg", "first_seen_at": "2026-10-23T19:11:31+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4628", "first_seen_at": "2026-10-23T23:44:52+00:00"}]
---

# Keycloak has Improper Access Control that allows attackers with valid credentials to bypass the allowRemoteResourceManagement=false

Keycloak's User-Managed Access resource_set endpoint does not fully enforce the allowRemoteResourceManagement=false restriction on PUT requests. An attacker with valid credentials can modify protected resources, which affects data integrity.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- maven:org.keycloak:keycloak-services affected <= 26.6.0 fixed ?
- vendor:redhat build of keycloak affected ? fixed ?

## How to check

Check whether any realm client's UMA resource server sets allowRemoteResourceManagement to false and whether the UMA resource_set endpoint is in use. Check the running Keycloak version against maven org.keycloak:keycloak-services <= 26.6.0.

## Fix

Upgrade to a Keycloak release newer than 26.6.0; the fixed version is unknown from the sources.

## Timeline

- 2026-10-23T19:11:31+00:00 ghsa https://github.com/advisories/GHSA-4pgc-gfrr-wcmg
- 2026-10-23T23:44:52+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-4628

## From the sources

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.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_