CVE-2026-90997
Keycloak-services: keycloak: replay protection bypass leads to unauthorized access via database driver semantics mismatch
CVSS Score
7.4
EPSS Score
0.4%
EPSS Percentile
31th
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.
| CWE | CWE-294 |
| Vendor | keycloak |
| Product | keycloak |
| Published | Sep 17, 2026 |
| Last Updated | Sep 25, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Affected Versions
Keycloak / Keycloak
26.7.0 < 26.7.4
Red Hat / Red Hat Build of Keycloak
All versions affected Red Hat / Red Hat Build of Keycloak
All versions affected References
Credits
Red Hat would like to thank Bruno Oliveira of IBM in collaboration with OpenAI for reporting this issue.