Description
Mattermost versions 10.5.x <= 10.5.8, 9.11.x <= 9.11.17 fail to properly validate authorization for team scheme role modifications which allows Team Admins to demote Team Members to Guests via the PUT /api/v4/teams/team-id/members/user-id/schemeRoles API endpoint.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mattermost | Mattermost | 10.5.0 – ≤ 10.5.8, 9.11.0 – ≤ 9.11.17 | 10.10.0 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Go | github.com/mattermost/mattermost-server | >= 10.5.0, < 10.5.9 | 10.5.9 | GHSA-4276-cm8c-788h |
| Go | github.com/mattermost/mattermost-server | >= 9.11.0, < 9.11.18 | 9.11.18 | GHSA-4276-cm8c-788h |
| Go | github.com/mattermost/mattermost-server | >= 9.11.0+incompatible, < 9.11.18+incompatible · >= 10.5.0+incompatible, < 10.5.9+incompatible | 9.11.18+incompatible, 10.5.9+incompatible | GO-2025-3902 |
| Go | github.com/mattermost/mattermost-server/v5 | <= 5.39.3 | — | GHSA-4276-cm8c-788h |
| Go | github.com/mattermost/mattermost-server/v5 | all versions | — | GO-2025-3902 |
| Go | github.com/mattermost/mattermost-server/v6 | <= 6.7.2 | — | GHSA-4276-cm8c-788h |
| Go | github.com/mattermost/mattermost-server/v6 | all versions | — | GO-2025-3902 |
| Go | github.com/mattermost/mattermost/server/v8 | < 8.0.0-20250721095846-c602a4a78e1f | 8.0.0-20250721095846-c602a4a78e1f | GHSA-4276-cm8c-788h |
Advisories 1
- WID-SEC-2025-1625 Mattermost Server und Plugins: Mehrere Schwachstellen BSI CERT-Bund (WID) · Aug 21, 2025