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    CVE-2026-109081

    A flaw was found in Keycloak. The Dynamic Client Registration (DCR) endpoint does not properly validate authorization when processing the deprecated defaultRoles field. An authenticated attacker with client creation privileges or an Initial Access Token (IAT) can inject excessive roles into the realm's default roles configuration. This causes clients across the realm to generate bloated access tokens, resulting in performance and memory degradation that can lead to a Denial of Service (DoS).

    Published:Nov 5, 2026
    Last Modified:Nov 6, 2026
    EPS:Nov 6, 2026
    EPSS Score:
    CVSS Score:6.8

    Affected Products

    Vendor
    Keycloak
    Product
    Keycloak
    Vendor
    Redhat
    Product
    Build Keycloak
    Vendor
    Redhat
    Product
    Red Hat Single Sign On

    Exploits

    No exploit reference

    Common Weakness Enumeration

    CWE-862 Missing Authorization

    Common Attack Pattern Enumeration and Classification (CAPEC)

    CAPEC-665 Exploitation of Thunderbolt Protection Flaws

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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
    CVE-2026-109081 — Keycloak, Redhat (Medium 6.8) | CVE-DB