Improper access control in Keycloak - CVE-2026-4628
Published: September 10, 2026
Vulnerability identifier: #VU148944
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-4628
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to modify protected resources without authorization.
The vulnerability exists due to improper access control in the User-Managed Access (UMA) resource_set endpoint when handling PUT operations. A remote user can send a PUT request to bypass the allowRemoteResourceManagement=false restriction and modify protected resources.
Affected software
Keycloak
How to mitigate CVE-2026-4628
Install security update from vendor's website.
Keycloak - update to 26.6.2