GHSA-4276-cm8c-788h
Mattermost Fails to Properly Validate Team Role Modification
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Go | github.com/mattermost/mattermost-server | >= 10.5.0, < 10.5.9 | 10.5.9 |
| Go | github.com/mattermost/mattermost-server | >= 9.11.0, < 9.11.18 | 9.11.18 |
| Go | github.com/mattermost/mattermost/server/v8 | < 8.0.0-20250721095846-c602a4a78e1f | 8.0.0-20250721095846-c602a4a78e1f |
| Go | github.com/mattermost/mattermost-server/v5 | <= 5.39.3 | no fix listed |
| Go | github.com/mattermost/mattermost-server/v6 | <= 6.7.2 | no fix listed |
Details
As written in the advisory (Markdown source, shown as plain text).
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.
References
External links from the advisory. They lead to third-party sites.