Advisoriesby IbisRed HatCVE-2026-1609
Red Hat Keycloak.: improper access control
Fix: upgrade to 26.5.3 or later
A flaw was found in Keycloak. When the JSON Web Token (JWT) authorization grant preview feature is enabled and a user account is disabled, Keycloak fails to validate the user’s disabled status during JWT authorization grant processing. A remote attacker with low privileges can exploit this improper access control vulnerability by presenting a valid assertion token from an external identity provider to obtain a JWT for a disabled user. This allows unauthorized access to sensitive resources.
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| Keycloak Product | >= 26.5.0, < 26.5.3 | 26.5.3 |
| Red Hat JBoss Enterprise Application Platform 8 Product | all versions | No fix yet |
| all versions | No fix yet | |
| all versions | No fix yet | |
| all versions | No fix yet | |
| all versions | No fix yet | |
| all versions | No fix yet | |
| Red Hat JBoss Enterprise Application Platform Expansion Pack Product | all versions | No fix yet |
| all versions | No fix yet | |
| all versions | No fix yet | |
| all versions | No fix yet | |
| all versions | No fix yet |
Details and references
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- Severity from
- the vendor (its own CVE record or advisory)
- Weakness
- CWE-284
- www.cve.org/CVERecord?id=CVE-2026-1609
- nvd.nist.gov/vuln/detail/CVE-2026-1609
- access.redhat.com/security/cve/CVE-2026-1609
- bugzilla.redhat.com/show_bug.cgi?id=2435257
- github.com/keycloak/keycloak/issues/46144
- github.com/keycloak/keycloak/releases/tag/26.5.3
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-1609.json