Keycloak: keycloak: denial of service via malformed authorization header_CVE-2026-9803

{
    "lastseen": "",
    "description": "A flaw was found in Keycloak's ClientRegistrationAuth component. A remote unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with a malformed 'Authorization: Bearer' header to any client registration endpoint. This can lead to an ArrayIndexOutOfBoundsException, causing the server to return an HTTP 500 error and resulting in a Denial of Service (DoS) for the affected service.",
    "published": "2026-05-28T04:47:10.485Z",
    "modified": "2026-05-28T04:47:10.485Z",
    "type": "cve",
    "title": "Keycloak: keycloak: denial of service via malformed authorization header",
    "source": "redhat",
    "references": "https://access.redhat.com/security/cve/CVE-2026-9803\nhttps://bugzilla.redhat.com/show_bug.cgi?id=2482465",
    "id": "CVE-2026-9803",
    "bulletinFamily": "",
    "cwe": [
        "CWE-125"
    ],
    "cvelist": null,
    "sourceData": "",
    "sourceHref": "",
    "cvss": {
        "score": 5.3,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
        "version": "3.1"
    },
    "cvss2": [],
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        "baseScore": 0,
        "baseSeverity": "",
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        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
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    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Red Hat Build of Keycloak",
    "version": "",
    "vendor": "Red Hat",
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    "ai_score": 0
}