Mattermost group syncable endpoints allow privilege escalation via scheme_admin_CVE-2026-7387

{
    "lastseen": "",
    "description": "Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Mattermost fails to require role-management authorization when setting the scheme_admin flag on group syncable link and patch endpoints, which allows a user with group-link permissions to escalate themselves and group members to team or channel admin via crafted API requests.. Mattermost Advisory ID: MMSA-2026-00665",
    "published": "2026-06-12T15:54:10.103Z",
    "modified": "2026-06-12T15:54:10.103Z",
    "type": "cve",
    "title": "Mattermost group syncable endpoints allow privilege escalation via scheme_admin",
    "source": "Mattermost",
    "references": "https://mattermost.com/security-updates",
    "id": "CVE-2026-7387",
    "bulletinFamily": "",
    "cwe": [
        "CWE-863"
    ],
    "cvelist": null,
    "sourceData": "Mattermost Mattermost 11.6.0\nMattermost Mattermost 11.5.0\nMattermost Mattermost 10.11.0\nMattermost Mattermost 10.11.0",
    "sourceHref": "",
    "cvss": {
        "score": 8.8,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
        "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": "Mattermost",
    "version": "11.6.0",
    "vendor": "Mattermost",
    "ai_description": "Mattermost fails to require role-management authorization when setting the scheme_admin flag on group syncable link and patch endpoints, allowing a user with group-link permissions to escalate themselves and group members to team or channel admin via crafted API requests.",
    "ai_severity": "High",
    "ai_vendor": "Mattermost",
    "ai_product": "Mattermost",
    "ai_version": "11.6.0, 11.5.0, 10.11.0, 10.11.15, 10.11.16",
    "ai_score": 8.8
}