CWE-603
Use of Client-Side Authentication
A client/server product performs authentication within client code but not in server code, allowing server-side authentication to be bypassed via a modified client that omits the authentication check.
CVE-2026-8830 (GCVE-0-2026-8830)
Vulnerability from cvelistv5 – Published: 2026-05-19 06:04 – Updated: 2026-05-19 16:32
VLAI
Title
Keycloak: org.keycloak/keycloak-services: keycloak: policy bypass during webauthn credential registration via client-side javascript manipulation
Summary
A flaw was found in Keycloak. An authenticated user can bypass configured WebAuthn policies during credential registration by manipulating client-side JavaScript. This occurs because the server-side processAction() fails to validate that the newly created credential's parameters, such as public key algorithms, match the realm's configured WebAuthn policies. This could lead to the creation of credentials that do not adhere to administrative security requirements, potentially weakening the overall security posture of the system by allowing non-compliant authentication methods.
Severity
4.3 (Medium)
CWE
- CWE-603 - Use of Client-Side Authentication
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://access.redhat.com/security/cve/CVE-2026-8830 | vdb-entryx_refsource_REDHAT |
| https://bugzilla.redhat.com/show_bug.cgi?id=2479565 | issue-trackingx_refsource_REDHAT |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Red Hat | Red Hat Build of Keycloak |
cpe:/a:redhat:build_keycloak: |
Date Public
2026-05-19 05:00
Credits
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Mitigation
Phase: Architecture and Design
Description:
- Do not rely on client side data. Always perform server side authentication.
No CAPEC attack patterns related to this CWE.