CVE-2026-4628: Keycloak improper access control in UMA resource_set endpoint

CVE-2026-4628 · Severity: medium · CVSS 4.3 · Published 2026-03-23

Keycloak, an open-source identity and access management solution, contains a security flaw in its resource management component. An attacker with valid login credentials can bypass security restrictions to modify protected resources that should be locked. This could lead to unauthorized changes to sensitive data or system configurations, potentially compromising the integrity of the identity management system.

Technologies: Keycloak, org.keycloak:keycloak-services (Maven), Redhat Build Of Keycloak. Vendors: Keycloak, Maven, Redhat.

Quick answers

Is CVE-2026-4628 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-4628 being exploited in the wild.
How severe is CVE-2026-4628?
Medium severity, with a CVSS score of 4.3, published 23 March 2026.
Which products and versions are affected?
Keycloak <= 26.6.0; org.keycloak:keycloak-services (Maven) <= 26.6.0, ECOSYSTEM:introduced=0,last_affected=26.6.0.
Is there a fix for CVE-2026-4628?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-4628 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-4628?
Check whether you run Keycloak, org.keycloak:keycloak-services (Maven) or Redhat Build Of Keycloak at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

An improper access control vulnerability (CWE-284) exists in Keycloak's User-Managed Access (UMA) resource_set endpoint. The vulnerability stems from incomplete enforcement of access control checks during HTTP PUT operations. Specifically, an attacker with valid credentials can bypass the 'allowRemoteResourceManagement=false' configuration setting. This allows unauthorized modification of protected resources via the resource_set endpoint. The issue affects versions up to and including 26.6.0; as of the advisory date, no patched version is specified.

Affected products

  • Keycloak Keycloak <= 26.6.0

Identifiers

  • CVE-2026-4628
  • GHSA-4pgc-gfrr-wcmg

Timeline

  • 2026-03-23: disclosed
  • 2026-03-23: advisory

References

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