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CVE-2026-1609

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

8.1 HighFix available

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.

Attack profile

How easy it is to exploit

Attack vector
Network
Complexity
Low
Privileges needed
Low
User interaction
None

What an attacker can affect

Confidentiality
High
Integrity
High
Availability
None

Exploit likelihood

0.56%Up 0.1 points since Jul 16, 2026
90%50%10%1%

What each source reports

CVE List Score used 8.1

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

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.

Record
CVE-2026-1609
CVSS 3.1
8.1 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weakness
CWE-284, CWE-284
Updated
2026-11-02
EUVDEUVD-2026-44841 8.1

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.

Record
EUVD-2026-44841
CVSS 3.1
8.1 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Updated
2026-11-02
GitHub AdvisoriesGHSA-5xcf-8m2w-ph6f 8.1

A flaw was found in Keycloak. When the JSON Web Token (JWT) authorization grant preview feature...

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.

Record
GHSA-5xcf-8m2w-ph6f
CVSS 3.1
8.1 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weakness
CWE-284
Updated
2026-11-02
NVD 8.1

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.

Record
CVE-2026-1609
CVSS 3.1
8.1 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weakness
CWE-284
Updated
2026-11-02
OSV 8.1

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

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.

Record
CVE-2026-1609
CVSS 3.1
8.1 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weakness
CWE-284
Updated
2026-11-06
OSVBIT-keycloak-2026-1609 No score

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

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.

Record
BIT-keycloak-2026-1609
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
keycloak
Bitnami
26.5.2 up to 26.5.3
26.5.3

History

History
RecordedChangedSources
factsOSV
first indexedCVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-1609 is a high vulnerability (CVSS 8.1) in Keycloak, published July 16, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.56%, the 46th percentile. Fixed in keycloak 26.5.3.

References

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