Org.keycloak/keycloak-quarkus-server: keycloak: unauthorized access via jwt authorization grant with disabled users
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-284.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Keycloak | Keycloak | 26.5.0 to before 26.5.3 | 26.5.3 | Patch available | CNA |
| Red Hat | Red Hat JBoss Enterprise Application Platform 8 | — | — | Not affected | CNA |
| Red Hat | Red Hat JBoss Enterprise Application Platform 8 | — | — | Not affected | CNA |
| Red Hat | Red Hat JBoss Enterprise Application Platform 8 | — | — | Not affected | CNA |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | — | — | Not affected | CNA |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | — | — | Not affected | CNA |
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack | — | — | Not affected | CNA |
- Keycloak VendorKeycloak Affected 26.5.0 to before 26.5.3 Fixed in 26.5.3 Patch available CNA
- Red Hat JBoss Enterprise Application Platform 8 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat JBoss Enterprise Application Platform 8 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat JBoss Enterprise Application Platform 8 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat JBoss Enterprise Application Platform Expansion Pack VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat JBoss Enterprise Application Platform Expansion Pack VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat JBoss Enterprise Application Platform Expansion Pack VendorRed Hat Affected — Fixed in — Not affected CNA
Remediation
- Fix · CNA Keycloak (Keycloak) Fixed in 26.5.3
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
Not affected: 2 products
- Red Hat JBoss Enterprise Application Platform 8
- Red Hat JBoss Enterprise Application Platform Expansion Pack
Timeline
- 2026-10-02 Threatist record created from CVE-2026-1609
- 2026-10-03 Alias added: GHSA-5xcf-8m2w-ph6f
References
More Keycloak vulnerabilities
- TI-2022-03994 Cross-site scripting in keycloak CVSS 3.1CRITICAL 10.0
- TI-2017-05120 It was found that the Keycloak Node.js adapter 2.5 - 3.0 did not handle invalid tokens… CVSS 3.0CRITICAL 9.8
- TI-2017-08952 Weak password recovery in Red Hat Keycloak CVSS 3.0HIGH 8.8
- TI-2014-03024 The org.keycloak.services.resources.SocialResource.callback method in JBoss KeyCloak… CVSS 3.0HIGH 8.8
- TI-2017-08950 Insufficient session expiration in Red Hat keycloak CVSS 3.0HIGH 7.5
- TI-2014-02971 JBoss KeyCloak before 1.0.3.Final allows remote attackers to cause a denial of service… CVSS 3.0HIGH 7.5
Sources
- CVE-2026-1609 · CVE Program
- CVE-2026-1609 · NVD
- FIRST EPSS
- GHSA-5xcf-8m2w-ph6f · GitHub Advisory Database · CC BY 4.0
- CVE-2026-1609 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences