Cyber Resilience

CVE-2026-8830

Redhat Build Of Keycloak

Published
19 May 2026
Modified
23 July 2026
Patch / advisory
View advisory
CVSS Score v3.1 4.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
EPSS Score 0.0039 32th percentile
Risk Priority 37 floored blend · peak EPSS

Summary

CVE-2026-8830 is a medium-severity Use of Client-Side Authentication (CWE-603) vulnerability in Redhat Build Of Keycloak. Its CVSS base score is 4.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 32th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and IA-2 (Identification and Authentication (Organizational Users)) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

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…

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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.

CWE(s)
CWE-603

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-37978Same product: Redhat Build Of Keycloak
CVE-2026-7571Same product: Redhat Build Of Keycloak
CVE-2026-9798Same product: Redhat Build Of Keycloak
CVE-2026-4636Same product: Redhat Build Of Keycloak
CVE-2026-9799Same product: Redhat Build Of Keycloak
CVE-2026-9099Same product: Redhat Build Of Keycloak
CVE-2026-7307Same product: Redhat Build Of Keycloak
CVE-2026-9083Same product: Redhat Build Of Keycloak
CVE-2026-9087Same product: Redhat Build Of Keycloak
CVE-2026-4630Same product: Redhat Build Of Keycloak

Affected Assets

redhat
build of keycloak
all versions

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V10.4.10
  • V10.4.15
  • V10.4.16
  • V10.7.1

Mitigating Controls (NIST 800-53 r5) AI

AC-3 Access Enforcement good match

Enforces access authorizations on the server, making client-side bypass ineffective.

IA-2 Identification and Authentication (Organizational Users) good match

Requires server-side identification and authentication of users before granting access.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-03 full match
prevents

Server-enforced authentication directly prevents client-only checks from being bypassed.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.5 Secure authentication full match
degrades

Requires server-side authentication mechanisms that directly prevent client-only checks.

A.8.27 Secure system architecture and engineering principles mostly match
prevents

Promotes secure architecture principles that reject client-only authentication designs.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect missing server-side authentication checks.

A.8.26 Application security requirements partial match
prevents

Defines application security requirements that include server-side authentication enforcement.

A.8.28 Secure coding partial match
prevents

Secure coding standards discourage reliance on client-side authentication logic.

A.8.3 Information access restriction partial match
mitigates

Enforces access restrictions that must be validated on the server, mitigating client-side bypass.

References