Description
A flaw was found in Keycloak. When deployed in stateless mode with MySQL or MariaDB, a mismatch in row-count semantics between the database driver and Keycloak's application logic allows an attacker to bypass replay protection. This vulnerability enables an attacker who intercepts single-use security artifacts, such as JWT client assertions, DPoP proofs, or one-time password (TOTP) codes, to replay them. Successful exploitation grants unauthorized access to the token endpoint or login flow.
Published: 2026-09-17
Score: 7.4 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

Vendor Workaround

To mitigate this issue, configure the JDBC connection string for MySQL/MariaDB to explicitly set `useAffectedRows=true`. This ensures the database driver correctly reports affected rows, preventing the replay protection bypass. This mitigation is applicable only when Keycloak is deployed in stateless mode and utilizes MySQL or MariaDB as its database. A restart of the Keycloak service will be required for the configuration change to take effect.

Tracking

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Advisories

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History

Tue, 22 Sep 2026 19:30:00 +0000


Tue, 22 Sep 2026 19:00:00 +0000

Type Values Removed Values Added
Title Keycloak: Replay protection bypass leads to unauthorized access via database driver semantics mismatch Keycloak-services: keycloak: replay protection bypass leads to unauthorized access via database driver semantics mismatch
First Time appeared Redhat
Redhat build Keycloak
CPEs cpe:/a:redhat:build_keycloak:
Vendors & Products Redhat
Redhat build Keycloak
References

Mon, 21 Sep 2026 22:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Fri, 18 Sep 2026 07:45:00 +0000

Type Values Removed Values Added
First Time appeared Keycloak
Keycloak keycloak
Vendors & Products Keycloak
Keycloak keycloak

Thu, 17 Sep 2026 19:00:00 +0000

Type Values Removed Values Added
Title keycloak-services: Keycloak: Replay protection bypass leads to unauthorized access via database driver semantics mismatch Keycloak: Replay protection bypass leads to unauthorized access via database driver semantics mismatch
References

Thu, 17 Sep 2026 12:15:00 +0000

Type Values Removed Values Added
Description A flaw was found in Keycloak. When deployed in stateless mode with MySQL or MariaDB, a mismatch in row-count semantics between the database driver and Keycloak's application logic allows an attacker to bypass replay protection. This vulnerability enables an attacker who intercepts single-use security artifacts, such as JWT client assertions, DPoP proofs, or one-time password (TOTP) codes, to replay them. Successful exploitation grants unauthorized access to the token endpoint or login flow.
Title keycloak-services: Keycloak: Replay protection bypass leads to unauthorized access via database driver semantics mismatch
Weaknesses CWE-294
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}

threat_severity

Important


Subscriptions

Keycloak Keycloak
Redhat Build Keycloak
cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-09-25T06:42:50.534Z

Reserved: 2026-09-14T14:53:37.815Z

Link: CVE-2026-90997

cve-icon Vulnrichment

Updated: 2026-09-21T21:07:48.577Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-17T19:17:06.740

Modified: 2026-09-22T19:16:56.183

Link: CVE-2026-90997

cve-icon Redhat

Severity : Important

Publid Date: 2026-09-16T14:21:23Z

Links: CVE-2026-90997 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-18T07:30:05Z

Weaknesses
  • CWE-294

    Authentication Bypass by Capture-replay