A flaw was found in the Keycloak server during refresh token processing, specifically in the TokenManager class responsible for enforcing refresh token reuse policies. When strict refresh token rotation is enabled, the validation and update of refresh token usage are not performed atomically. This allows concurrent refresh requests to bypass single-use enforcement and issue multiple access tokens from the same refresh token. As a result, Keycloak’s refresh token rotation hardening can be undermined.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

To mitigate this issue, configure the `refreshTokenMaxReuse` policy in Keycloak to a value greater than zero. This prevents the race condition by allowing a limited number of reuses for refresh tokens, thereby maintaining the integrity of the Refresh Token Rotation hardening measure. Consult Keycloak documentation for specific configuration instructions. Changes to Keycloak configuration typically require a service restart or redeployment to take effect.

History

Wed, 21 Jan 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Low


Wed, 21 Jan 2026 06:00:00 +0000

Type Values Removed Values Added
Description A flaw was found in the Keycloak server during refresh token processing, specifically in the TokenManager class responsible for enforcing refresh token reuse policies. When strict refresh token rotation is enabled, the validation and update of refresh token usage are not performed atomically. This allows concurrent refresh requests to bypass single-use enforcement and issue multiple access tokens from the same refresh token. As a result, Keycloak’s refresh token rotation hardening can be undermined.
Title Org.keycloak.protocol.oidc: keycloak refresh token reuse bypass via toctou race condition
First Time appeared Redhat
Redhat build Keycloak
Redhat jboss Enterprise Application Platform
Redhat jbosseapxp
Redhat red Hat Single Sign On
Weaknesses CWE-367
CPEs cpe:/a:redhat:build_keycloak:
cpe:/a:redhat:jboss_enterprise_application_platform:8
cpe:/a:redhat:jbosseapxp
cpe:/a:redhat:red_hat_single_sign_on:7
Vendors & Products Redhat
Redhat build Keycloak
Redhat jboss Enterprise Application Platform
Redhat jbosseapxp
Redhat red Hat Single Sign On
References
Metrics cvssV3_1

{'score': 3.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-01-21T05:52:22.495Z

Reserved: 2026-01-16T07:03:59.680Z

Link: CVE-2026-1035

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-01-21T06:15:46.937

Modified: 2026-01-21T06:15:46.937

Link: CVE-2026-1035

cve-icon Redhat

Severity : Low

Publid Date: 2026-01-21T00:00:00Z

Links: CVE-2026-1035 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses