CVE-2026-8830

Description

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.

Statement

A Moderate security flaw was found in Keycloak's WebAuthn credential registration process. This issue allows an authenticated attacker to bypass configured WebAuthn policies, such as algorithm requirements or user verification, by manipulating client-side JavaScript during registration. This bypass could lead to the registration of credentials that do not meet the intended security standards, potentially weakening the overall authentication posture.

Mitigation

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score4.3N/A4.3
Attack VectorNetworkN/ANetwork
Attack ComplexityLowN/ALow
Privileges RequiredLowN/ALow
User InteractionNoneN/ANone
ScopeUnchangedN/AUnchanged
ConfidentialityNoneN/ANone
Integrity ImpactLowN/ALow
Availability ImpactNoneN/ANone

Vector

Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Understanding the Weakness (CWE)

Access Control

Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity

Acknowledgements

Red Hat would like to thank Martin Bartoš (RedHat) for reporting this issue.

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