Keycloak: org.keycloak/keycloak-services: keycloak: policy bypass during webauthn credential registration via client-side javascript manipulation

Summary

CVE	CVE-2026-8830
State	PUBLISHED
Assigner	redhat
Source Priority	CVE Program / NVD first with legacy fallback
Published	2026-05-19 07:16:30 UTC
Updated	2026-06-26 08:16:25 UTC
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.

Risk And Classification

Primary CVSS: v3.1 4.3 MEDIUM from [email protected]

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

EPSS: 0.003920000 probability, percentile 0.310020000 (date 2026-06-29)

Problem Types: CWE-603 | CWE-603 Use of Client-Side Authentication

Version	Source	Type	Score	Severity	Vector
3.1	[email protected]	Secondary	4.3	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N`
3.1	CNA	CVSS	4.3	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N`

CVSS v3.1 Breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

None

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

NVD Known Affected Configurations (CPE 2.3)

Type	Vendor	Product	Version	Update	Edition	Language
Application	Redhat	Build Of Keycloak	-	All	All	All

Vendor Declared Affected Products

Source	Vendor	Product	Version	Platforms
CNA	Red Hat	Red Hat Build Of Keycloak 26.4	unaffected 26.4.13-1 * rpm	Not specified
CNA	Red Hat	Red Hat Build Of Keycloak 26.4	unaffected 26.4-19 * rpm	Not specified
CNA	Red Hat	Red Hat Build Of Keycloak 26.4	unaffected 26.4-19 * rpm	Not specified
CNA	Red Hat	Red Hat Build Of Keycloak 26.4.13	Not specified	Not specified
CNA	Red Hat	Red Hat Build Of Keycloak 26.6	unaffected 26.6.3-3 * rpm	Not specified
CNA	Red Hat	Red Hat Build Of Keycloak 26.6	unaffected 26.6-6 * rpm	Not specified
CNA	Red Hat	Red Hat Build Of Keycloak 26.6	unaffected 26.6-6 * rpm	Not specified
CNA	Red Hat	Red Hat Build Of Keycloak 26.6.3	Not specified	Not specified

References

Reference	Source	Link	Tags
access.redhat.com/errata/RHSA-2026:25098	[email protected]	access.redhat.com
access.redhat.com/errata/RHSA-2026:25097	[email protected]	access.redhat.com
access.redhat.com/security/cve/CVE-2026-8830	[email protected]	access.redhat.com	Vendor Advisory
access.redhat.com/errata/RHSA-2026:30049	[email protected]	access.redhat.com
bugzilla.redhat.com/show_bug.cgi	[email protected]	bugzilla.redhat.com	Issue Tracking, Vendor Advisory
access.redhat.com/errata/RHSA-2026:30050	[email protected]	access.redhat.com
CVE Program record	CVE.ORG	www.cve.org	canonical
NVD vulnerability detail	NVD	nvd.nist.gov	canonical, analysis

Vendor Comments And Credit

Discovery Credit

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

Additional Advisory Data

Source	Time	Event
CNA	2026-05-18T13:09:00.257Z	Reported to Red Hat.
CNA	2026-05-19T05:00:04.741Z	Made public.

Workarounds

CNA: 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.

There are currently no legacy QID mappings associated with this CVE.