Keycloak: Replay protection bypass leads to unauthorized access via database driver semantics mismatch

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-90997
StatePUBLISHED
Assignerredhat
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-17 19:17:06 UTC
Updated2026-09-17 19:17:06 UTC
DescriptionA 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.

Risk And Classification

Primary CVSS: v3.1 7.4 HIGH from [email protected]

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Problem Types: CWE-294 | CWE-294 CWE-294 Authentication Bypass by Capture-replay

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary7.4HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
3.1CNACVSS7.4HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Keycloak Keycloak affected 26.7.0 26.7.4 semver Not specified

References

ReferenceSourceLinkTags
github.com/keycloak/keycloak [email protected] github.com
access.redhat.com/security/cve/cve-2026-90997 [email protected] access.redhat.com
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