CVE-2026-8830: Keycloak Policy Bypass During WebAuthn Credential Vulnerability
MODERATECVE-2026-8830 is a MODERATE (CVSS 4.3) policy bypass during webauthn credential vulnerability (CWE-603: Use of Client-Side Authentication) affecting Keycloak libraries in the Maven ecosystem. The issue involves policy bypass during webauthn credential registration via client-side javascript manipulation. Remediation is available by upgrading affected packages to version 26.6.3.
CVE-2026-8830 at a Glance
Security Impact
CVSS: 4.3
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N).
How to Fix CVE-2026-8830
To remediate this vulnerability, upgrade all affected Keycloak dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
<dependency>
<groupId>org.keycloak</groupId>
<artifactId>keycloak-services</artifactId>
<version>26.6.3</version>
</dependency>Run the following command in your project directory to verify that all resolved dependencies use the patched release:
mvn dependency:tree -Dincludes=org.keycloakHow to Check if You Are Affected
To determine whether your Java application is affected by CVE-2026-8830, inspect your build dependencies using the Maven Dependency Plugin:
mvn dependency:tree -Dincludes=org.keycloakAnalyze the terminal output to locate any version of Keycloak in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 26.6.3), your application is affected.
Note: The mvn dependency:tree -Dincludes=org.keycloak command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-603: Use of Client-Side Authentication, where 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. In Keycloak, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-8830 Affected Keycloak Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
org.keycloak:keycloak-services
|
Maven |
< 26.6.3
|
26.6.3
|
References
Frequently Asked Questions
What is CVE-2026-8830?
Which Keycloak versions are affected?
What version fixes CVE-2026-8830?
Is keycloak-services affected?
What is the CVSS score of CVE-2026-8830?
What CWE is associated with CVE-2026-8830?
How can I check Maven dependencies for CVE-2026-8830?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-g8vr-x4qh-25qg",
"modified" : "2026-06-26T09:30:45Z",
"published" : "2026-05-19T09:31:20Z",
"aliases" : [ "CVE-2026-8830" ],
"summary" : "Keycloak: Policy bypass during WebAuthn credential registration via client-side JavaScript manipulation",
"details" : "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" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Maven",
"name" : "org.keycloak:keycloak-services"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "26.6.3"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 26.6.2"
}
} ],
"references" : [ {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-8830"
}, {
"type" : "WEB",
"url" : "https://github.com/keycloak/keycloak/issues/49133"
}, {
"type" : "WEB",
"url" : "https://github.com/keycloak/keycloak/pull/49344"
}, {
"type" : "WEB",
"url" : "https://github.com/keycloak/keycloak/commit/47b9aef70948564151af85fd52e0d7e508c76490"
}, {
"type" : "WEB",
"url" : "https://github.com/keycloak/keycloak/commit/d3da77ef363d698e7a74470ba52fcdce09e394c4"
}, {
"type" : "WEB",
"url" : "https://access.redhat.com/errata/RHSA-2026:25097"
}, {
"type" : "WEB",
"url" : "https://access.redhat.com/errata/RHSA-2026:25098"
}, {
"type" : "WEB",
"url" : "https://access.redhat.com/errata/RHSA-2026:30049"
}, {
"type" : "WEB",
"url" : "https://access.redhat.com/errata/RHSA-2026:30050"
}, {
"type" : "WEB",
"url" : "https://access.redhat.com/security/cve/CVE-2026-8830"
}, {
"type" : "WEB",
"url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2479565"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/keycloak/keycloak"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-603" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2026-06-04T17:28:15Z",
"nvd_published_at" : "2026-05-19T07:16:30Z"
}
}