GHSA-6hxm-w4hv-vgvwHighCVSS 8.8

Mattermost doesn't require role-management authorization when setting the scheme_admin flag on group syncable link and patch endpoints

Published
June 12, 2026
Last Modified
August 24, 2026

🔗 CVE IDs covered (1)

CVE-2026-7387 →

📋 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 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

🎯 Affected products4

  • go/github.com/mattermost/mattermost-server:= 11.6.0
  • go/github.com/mattermost/mattermost-server:>= 11.5.0, <= 11.5.4
  • go/github.com/mattermost/mattermost-server:>= 10.11.0, <= 10.11.15
  • go/github.com/mattermost/mattermost/server/v8:>= 8.0.0-20250731163400-5b955468ea1e, < 8.0.0-20260506065351-202d125afa87

🔗 References (17)