Improperly implemented security check for standard in Keycloak - CVE-2026-1486
Published: September 10, 2026
Vulnerability identifier: #VU148916
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-1486
CWE-ID: CWE-358
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to obtain valid access tokens.
The vulnerability exists due to an improperly implemented security check in the jwt-authorization-grant flow when processing JWT assertions from a disabled Identity Provider. A remote user can submit a valid JWT assertion signed with the disabled Identity Provider\'s signing key to obtain valid access tokens.
The issuer lookup mechanism does not filter Identity Provider configurations with isEnabled=false.
Affected software
Keycloak
Red Hat build of Keycloak
Red Hat build of Keycloak
How to mitigate CVE-2026-1486
Install security update from vendor's website.
Keycloak - addressed in versions 26.4.9, 26.5.3
Red Hat build of Keycloak - update to 26.4.9
Red Hat build of Keycloak - update to 26.4.9