High severity · published Jul 16, 2026
CVE-2026-1609
Org.keycloak/keycloak-quarkus-server: keycloak: unauthorized access via jwt authorization grant with disabled users
8.1
CVSS
0.6%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 47% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Keycloak · Keycloak
26.5.0 before 26.5.3 · source: vendor
BO
Build OF Keycloak · Redhat
26.5.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-1609
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-1609
Vendor Advisory
https://access.redhat.com/security/cve/CVE-2026-1609
Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=2435257
Issue Tracking
https://github.com/keycloak/keycloak/issues/46144
Release Notes
https://github.com/keycloak/keycloak/releases/tag/26.5.3
Vendor Advisory
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-1609.json
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