CVE-2026-1609Org.keycloak/keycloak-quarkus-server: keycloak: unauthorized access via jwt authorization grant with disabled users
- 8.1HighCVSS base score
- 0.56%Exploitation in 30 daysEPSS · top 53% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By redhat
- 6 months later
· 6 months later
Published
- 25 days later
· 25 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| redhatCNA (assigner) | 3.1 | High8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
| redhat-SADPADP (enrichment) | 3.1 | High8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
| NVDNVD · Analyzed | 3.1 | High8.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.56% · top 53% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.1.
Affected products
- affected 26.5.0 – < 26.5.3
Red Hat · Red Hat JBoss Enterprise Application Platform 8
All versions: unaffected
Red Hat · Red Hat JBoss Enterprise Application Platform 8
All versions: unaffected
Red Hat · Red Hat JBoss Enterprise Application Platform 8
All versions: unaffected
Red Hat · Red Hat JBoss Enterprise Application Platform Expansion Pack
All versions: unaffected
Red Hat · Red Hat JBoss Enterprise Application Platform Expansion Pack
All versions: unaffected
Red Hat · Red Hat JBoss Enterprise Application Platform Expansion Pack
All versions: unaffected
What to do
Workaround: To mitigate this issue, ensure that the `jwt-authorization-grant` preview feature is not enabled in Keycloak deployments. This feature is typically disabled by default. If it has been explicitly enabled, it should be disabled to prevent unauthorized access by disabled user accounts. Consult Keycloak documentation for specific instructions on managing preview features and configuration. A restart of the Keycloak service may be required after disabling the feature for the changes to take effect.
References
References5
- https://access.redhat.com/security/cve/CVE-2026-1609 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2435257 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://github.com/keycloak/keycloak/issues/46144 (opens in a new tab)
- https://github.com/keycloak/keycloak/releases/tag/26.5.3 (opens in a new tab)
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-1609.json (opens in a new tab)x_sadp-csaf-vex
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-44841 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-1609)Record last updated .