Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5 and 9.8.x <= 9.8.1 fail to disallow unsolicited invites to expose access to local channels, when shared channels are enabled, which allows a malicious remote to send an invite with the ID of an existing local channel, and that local channel will then become shared without the consent of the local admin.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Mattermost | Mattermost | 9.5.0 (including) | 9.5.7 (excluding) |
| Mattermost | Mattermost | 9.7.0 (including) | 9.7.6 (excluding) |
| Mattermost | Mattermost | 9.8.0 (including) | 9.8.2 (excluding) |
| Mattermost | Mattermost | 9.9.0 (including) | 9.9.0 (including) |