GitHub Advisoryadvisory · Maven
GHSA-h4wv-g838-66g3 Keycloak: Application-Level DoS via Scope Processing
HIGH
Official page ↗
- Aliases
- CVE-2026-4634
- Ecosystem
- Maven
- Packages
- org.keycloak:keycloak-services
- Severity
- High
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-1050
- Reviewed
- 2026-04-04
Affected packages
• Maven org.keycloak:keycloak-services: < 26.5.7 → fixed in 26.5.7
Description
A flaw was found in Keycloak. An unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with an excessively long scope parameter to the OpenID Connect (OIDC) token endpoint. This leads to high resource consumption and prolonged processing times, ultimately resulting in a Denial of Service (DoS) for the Keycloak server.
Related
Alias · CVE (1)
- CVE-2026-4634 A flaw was found in Keycloak. vulnerability
Weakness · CWE (1)
- CWE-1050 Excessive Platform Resource Consumption within a Loop weakness
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-4634 advisory
- https://github.com/keycloak/keycloak/issues/47716 web
- https://github.com/keycloak/keycloak/commit/b455ee4f28abb6f2120aff72fd179589cc5267a0 web
- https://access.redhat.com/errata/RHSA-2026:6475 web
- https://access.redhat.com/errata/RHSA-2026:6476 web
- https://access.redhat.com/errata/RHSA-2026:6477 web
- https://access.redhat.com/errata/RHSA-2026:6478 web
- https://access.redhat.com/security/cve/CVE-2026-4634 web
- https://bugzilla.redhat.com/show_bug.cgi?id=2450250 web
- https://github.com/keycloak/keycloak package