Open WebUI: Missing Access Check on Channel Members Endpoint for Standard Channels_CVE-2026-44559

{
    "lastseen": "",
    "description": "Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the GET /api/v1/channels/{id}/members endpoint only checks membership for group and dm channel types (lines 467-469). For standard channels \u2014 including private ones \u2014 there is no channel_has_access check before returning the member list. Any authenticated user who knows a private channel's UUID can enumerate all users with access to that channel. This vulnerability is fixed in 0.9.0.",
    "published": "2026-05-15T19:41:59.913Z",
    "modified": "2026-05-15T20:28:38.679Z",
    "type": "cve",
    "title": "Open WebUI: Missing Access Check on Channel Members Endpoint for Standard Channels",
    "source": "GitHub_M",
    "references": "https://github.com/open-webui/open-webui/security/advisories/GHSA-c7wp-3qh5-55pv",
    "id": "CVE-2026-44559",
    "bulletinFamily": "",
    "cwe": [
        "CWE-862"
    ],
    "cvelist": null,
    "sourceData": "open-webui open-webui < 0.9.0",
    "sourceHref": "",
    "cvss": {
        "score": 4.3,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/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": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "open-webui",
    "version": "< 0.9.0",
    "vendor": "open-webui",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}