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    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.

    Published:Apr 2, 2026
    Last Modified:Apr 16, 2026
    EPS:Apr 2, 2026
    EPSS Score:0.00088
    CVSS Score:7.5

    Affected Products

    Vendor
    Redhat
    Product
    Build Keycloak
    Vendor
    Redhat
    Product
    Build Of Keycloak

    Exploits

    No exploit reference

    Common Attack Pattern Enumeration and Classification (CAPEC)

    No CAPEC recorded yet

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    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High