CVE-2026-1609
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.56%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 8.1 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- EPSS
- 0.56% probability · 45th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-284
- Affected
- redhat/build of keycloak
- Source
- secalert@redhat.com
References
- https://access.redhat.com/security/cve/CVE-2026-1609Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2435257Issue Tracking, Vendor Advisory
- https://github.com/keycloak/keycloak/issues/46144Issue Tracking
- https://github.com/keycloak/keycloak/releases/tag/26.5.3Release Notes
- https://access.redhat.com/security/cve/CVE-2026-1609Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2435257Issue Tracking, Vendor Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-1609.jsonVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.