Mattermost versions 10.1.x <= 10.1.2, 10.0.x <= 10.0.2, 9.11.x <= 9.11.4, and 9.5.x <= 9.5.12 fail to prevent concurrently checking and updating the failed login attempts. which allows an attacker to bypass of "Max failed attempts" restriction and send a big number of login attempts before being blocked via simultaneously sending multiple login requests
| Software | From | Fixed in |
|---|---|---|
| mattermost / mattermost_server | 9.5.0 | 9.5.13 |
| mattermost / mattermost_server | 9.11.0 | 9.11.5 |
| mattermost / mattermost_server | 10.0.0 | 10.0.3 |
| mattermost / mattermost_server | 10.1.0 | 10.1.3 |