Keycloak: keycloak: cross-site scripting (xss) via case-insensitive uri validation bypass_CVE-2026-9086

{
    "lastseen": "",
    "description": "A flaw was found in Keycloak. A remote attacker with administrative privileges, specifically those with `manage-client` permission or access to client registration endpoints, could bypass client Uniform Resource Identifier (URI) validation. This is achieved by registering a malicious client with a specially crafted redirect URI using a case-insensitive `javascript:` or `data:` scheme. This Cross-Site Scripting (XSS) vulnerability allows for arbitrary code execution in the Keycloak origin when a victim clicks the crafted link, such as in the logout flow or the Admin Console.",
    "published": "2026-06-25T16:16:46.017Z",
    "modified": "2026-06-25T17:59:57.632Z",
    "type": "cve",
    "title": "Keycloak: keycloak: cross-site scripting (xss) via case-insensitive uri validation bypass",
    "source": "redhat",
    "references": "https://access.redhat.com/security/cve/CVE-2026-9086\nhttps://bugzilla.redhat.com/show_bug.cgi?id=2480170",
    "id": "CVE-2026-9086",
    "bulletinFamily": "",
    "cwe": [
        "CWE-79"
    ],
    "cvelist": null,
    "sourceData": "",
    "sourceHref": "",
    "cvss": {
        "score": 7.3,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
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            "privilegesRequired": "",
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Red Hat Build of Keycloak",
    "version": "",
    "vendor": "Red Hat",
    "ai_description": "",
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    "ai_vendor": "",
    "ai_product": "",
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    "ai_score": 0
}