CVE-2026-4634
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.
Package Versions Affected
Automatically patch vulnerabilities without upgrading
CVSS Version
Related Resources
References
https://nvd.nist.gov/vuln/detail/CVE-2026-4634, https://github.com/keycloak/keycloak/issues/47716, https://github.com/keycloak/keycloak/commit/b455ee4f28abb6f2120aff72fd179589cc5267a0, https://access.redhat.com/errata/RHSA-2026:6475, https://access.redhat.com/errata/RHSA-2026:6476, https://access.redhat.com/errata/RHSA-2026:6477, https://access.redhat.com/errata/RHSA-2026:6478, https://access.redhat.com/security/cve/CVE-2026-4634, https://bugzilla.redhat.com/show_bug.cgi?id=2450250, https://github.com/keycloak/keycloak
Basic Information
