What’s Vulnerable › Vulnerabilities

CVE-2026-1609: Org.keycloak/keycloak-quarkus-server: keycloak: unauthorized access via jwt authorization grant with disabled users

• Severity: high (CVSS 8.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-16 · updated 2026-08-09
• Weakness: CWE-284

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.

Affected products

• Red Hat build of Keycloak 26.4: 26.5.2

References

• https://access.redhat.com/security/cve/CVE-2026-1609
• https://bugzilla.redhat.com/show_bug.cgi?id=2435257
• https://github.com/keycloak/keycloak/issues/46144
• https://github.com/keycloak/keycloak/releases/tag/26.5.3
• https://access.redhat.com/security/cve/CVE-2026-1609
• https://bugzilla.redhat.com/show_bug.cgi?id=2435257
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-1609.json

Get alerted when CVE-2026-1609 or the next vulnerability affects your stack