CVE-2025-12421
published 2025-11-27CVE-2025-12421: Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to to verify that the token used during the code exchange…
critical9.9CVSS 3.1
AVNACLPRLUINSCCHIHAH
Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to to verify that the token used during the code exchange originates from the same authentication flow, which allows an authenticated user to perform account takeover via a specially crafted email address used when switching authentication methods and sending a request to the /users/login/sso/code-exchange endpoint. The vulnerability requires ExperimentalEnableAuthenticationTransfer to be enabled (default: enabled) and RequireEmailVerification to be disabled (default: disabled).
Affected
13 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| github.com | mattermost_mattermost-server | >= 10.11.0 < 10.11.5 | 10.11.5 |
| github.com | mattermost_mattermost-server | >= 10.12.0 < 10.12.2 | 10.12.2 |
| github.com | mattermost_mattermost-server | >= 10.5.0 < 10.5.13 | 10.5.13 |
| github.com | mattermost_mattermost-server | >= 11.0.0 < 11.0.3 | 11.0.3 |
| github.com | mattermost_mattermost_server_v8 | >= 0 < 8.0.0-20251022210333-acda1fb5dd46 | 8.0.0-20251022210333-acda1fb5dd46 |
| mattermost | mattermost | 10.11.0 – 10.11.4 | — |
| mattermost | mattermost | 10.12.0 – 10.12.1 | — |
| mattermost | mattermost | 10.5.0 – 10.5.12 | — |
| mattermost | mattermost | 11.0.0 – 11.0.2 | — |
| mattermost | mattermost_server | >= 10.11.0 < 10.11.5 | 10.11.5 |
| mattermost | mattermost_server | >= 10.12.0 < 10.12.2 | 10.12.2 |
| mattermost | mattermost_server | >= 10.5.0 < 10.5.13 | 10.5.13 |
| mattermost | mattermost_server | >= 11.0.0 < 11.0.3 | 11.0.3 |