{
"id": "GHSA-6hxm-w4hv-vgvw",
"aliases": [
"CVE-2026-7387"
],
"details": "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 fail 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",
"summary": "Mattermost doesn't require role-management authorization when setting the scheme_admin flag on group syncable link and patch endpoints",
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "11.6.0"
},
{
"fixed": "11.6.1"
}
]
}
],
"package": {
"name": "github.com/mattermost/mattermost-server",
"ecosystem": "Go"
},
"versions": [
"11.6.0"
]
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "11.5.0"
},
{
"fixed": "11.5.5"
}
]
}
],
"package": {
"name": "github.com/mattermost/mattermost-server",
"ecosystem": "Go"
},
"database_specific": {
"last_known_affected_version_range": "<= 11.5.4"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "10.11.0"
},
{
"fixed": "10.11.17"
}
]
}
],
"package": {
"name": "github.com/mattermost/mattermost-server",
"ecosystem": "Go"
},
"database_specific": {
"last_known_affected_version_range": "<= 10.11.15"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "8.0.0-20250731163400-5b955468ea1e"
},
{
"fixed": "8.0.0-20260506065351-202d125afa87"
}
]
}
],
"package": {
"name": "github.com/mattermost/mattermost/server/v8",
"ecosystem": "Go"
}
}
],
"modified": "2026-08-24T21:51:47Z",
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
}
],
"published": "2026-06-12T18:31:59Z",
"references": [
{
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-7387",
"type": "ADVISORY"
},
{
"url": "https://github.com/mattermost/mattermost/pull/36434",
"type": "WEB"
},
{
"url": "https://github.com/mattermost/mattermost/pull/36432",
"type": "WEB"
},
{
"url": "https://github.com/mattermost/mattermost/pull/36431",
"type": "WEB"
},
{
"url": "https://github.com/mattermost/mattermost/pull/36423",
"type": "WEB"
},
{
"url": "https://github.com/mattermost/mattermost/pull/36316",
"type": "WEB"
},
{
"url": "https://github.com/mattermost/mattermost/commit/d5f29c8ebbeb04460d16d9e2635ce50deeb78428",
"type": "WEB"
},
{
"url": "https://github.com/mattermost/mattermost/commit/a9e574a82633915f22071f0d7ca2b006f249ec2a",
"type": "WEB"
},
{
"url": "https://github.com/mattermost/mattermost/commit/8c72083414e675c97987374395e36d1f36b4bd8a",
"type": "WEB"
},
{
"url": "https://github.com/mattermost/mattermost/commit/202d125afa87fe39611686850fd82590c99ca344",
"type": "WEB"
},
{
"url": "https://github.com/mattermost/mattermost/commit/1ce2484a00c9821ee19708d2c46720e4855033a9",
"type": "WEB"
},
{
"url": "https://github.com/mattermost/mattermost/releases/tag/v10.11.16",
"type": "WEB"
},
{
"url": "https://github.com/mattermost/mattermost/releases/tag/v11.5.5",
"type": "WEB"
},
{
"url": "https://github.com/mattermost/mattermost/releases/tag/v11.6.2",
"type": "WEB"
},
{
"url": "https://github.com/mattermost/mattermost/releases/tag/v11.7.0",
"type": "WEB"
},
{
"url": "https://mattermost.com/security-updates",
"type": "WEB"
},
{
"url": "https://github.com/mattermost/mattermost",
"type": "PACKAGE"
}
],
"schema_version": "1.4.0",
"database_specific": {
"cwe_ids": [
"CWE-863"
],
"severity": "HIGH",
"github_reviewed": true,
"nvd_published_at": "2026-06-12T17:16:27Z",
"github_reviewed_at": "2026-08-24T21:51:47Z"
}
}