Client-Side Enforcement of Server-Side Security Affecting org.keycloak:keycloak-services package, versions [9.0.2,26.6.3)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JAVA-ORGKEYCLOAK-16875063
- published26 May 2026
- disclosed19 May 2026
- creditUnknown
Introduced: 19 May 2026
CVE-2026-8830 (opens in a new tab)How to fix?
Upgrade org.keycloak:keycloak-services to version 26.6.3 or higher.
Overview
org.keycloak:keycloak-services is an open source identity and access management solution for modern applications and services.
Affected versions of this package are vulnerable to Client-Side Enforcement of Server-Side Security through the processAction() registration flow in the WebAuthn authenticator components. An attacker can register a credential that does not match the realm’s WebAuthn policy by modifying the browser-side registration parameters or by using an authenticator that returns a different algorithm than requested. The server accepts and stores credentials with disallowed algorithms or other mismatched registration properties, and the same stored credential is then used for future logins without any server-side policy check, leaving users with WebAuthn credentials that do not enforce the administrator’s configured requirements.