Open WebUI: API key endpoint restrictions bypassed via `x-api-key` header — full message processing on restricted endpoints_CVE-2026-45339

{
    "lastseen": "",
    "description": "Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, Open WebUI allows admins to restrict which API endpoints an API key can access. When an API key is restricted from /api/v1/messages, requests using the Authorization: Bearer sk-... header are correctly blocked with 403. However, the same key sent via the x-api-key header bypasses the restriction entirely \u2014 the request is authenticated, the model is invoked, and a full response is returned. This vulnerability is fixed in 0.9.0.",
    "published": "2026-05-15T19:21:26.401Z",
    "modified": "2026-05-15T19:21:26.401Z",
    "type": "cve",
    "title": "Open WebUI: API key endpoint restrictions bypassed via `x-api-key` header \u2014 full message processing on restricted endpoints",
    "source": "GitHub_M",
    "references": "https://github.com/open-webui/open-webui/security/advisories/GHSA-57q6-fvp4-pqmm",
    "id": "CVE-2026-45339",
    "bulletinFamily": "",
    "cwe": [
        "CWE-863"
    ],
    "cvelist": null,
    "sourceData": "open-webui open-webui < 0.9.0",
    "sourceHref": "",
    "cvss": {
        "score": 6.5,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/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": "open-webui",
    "version": "< 0.9.0",
    "vendor": "open-webui",
    "ai_description": "",
    "ai_severity": "",
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    "ai_score": 0
}