CVE-2026-4634
Published: Apr 2, 2026
Modified: Apr 3, 2026
CVSS v3.1
7.5
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.
| Vendor | Product | Versions |
|---|---|---|
Red Hat | Red Hat build of Keycloak 26.2 | unaffected 26.2.15-1 - < * |
Red Hat | Red Hat build of Keycloak 26.2 | unaffected 26.2-18 - < * |
Red Hat | Red Hat build of Keycloak 26.2 | unaffected 26.2-18 - < * |
Red Hat | Red Hat build of Keycloak 26.2.15 | All versions |
Red Hat | Red Hat build of Keycloak 26.4 | unaffected 26.4.11-1 - < * |
Red Hat | Red Hat build of Keycloak 26.4 | unaffected 26.4-14 - < * |
Red Hat | Red Hat build of Keycloak 26.4 | unaffected 26.4-14 - < * |
Red Hat | Red Hat build of Keycloak 26.4.11 | All versions |
Weaknesses (CWE)
CVSS v3.1 Details
CVSS v3.1 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
References
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