---
id: CVE-2026-8830
title: A flaw was found in Keycloak
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…
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N'
cwe:
  - CWE-603
published: '2026-05-19'
updated: '2026-06-26'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-8830'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2026:25097'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:25098'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:30049'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:30050'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/security/cve/CVE-2026-8830'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2479565'
    label: secalert@redhat.com
tags:
  - nvd
epss: 0.0044
epssPercentile: 0.35504
ingestedAt: '2026-06-26T16:43:13.647Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.