GHSA-xpvf-6qcc-9jqc
Mattermost fails to validate team-specific upload_file permissions
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Go | github.com/mattermost/mattermost/server/v8 | < 8.0.0-20260107144005-c7f6efdfb035 | 8.0.0-20260107144005-c7f6efdfb035 |
| Go | github.com/mattermost/mattermost-server | < 5.3.2-0.20260107144005-c7f6efdfb035 | 5.3.2-0.20260107144005-c7f6efdfb035 |
| Go | github.com/mattermost/mattermost-server | >= 10.11.0-rc1, < 10.11.11 | 10.11.11 |
| Go | github.com/mattermost/mattermost-server | >= 11.2.0-rc1, < 11.2.3 | 11.2.3 |
| Go | github.com/mattermost/mattermost-server | >= 11.3.0-rc1, < 11.3.1 | 11.3.1 |
Details
As written in the advisory (Markdown source, shown as plain text).
Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to validate team-specific upload_file permissions which allows a guest user to post files in channels where they lack upload_file permission via uploading files in a team where they have permission and reusing the file metadata in a POST request to a different team. Mattermost Advisory ID: MMSA-2025-00553
References
External links from the advisory. They lead to third-party sites.