CVE-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 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).
| Software | From | Fixed in |
|---|---|---|
| mattermost / mattermost_server | 10.5.0 | 10.5.13 |
| mattermost / mattermost_server | 10.11.0 | 10.11.5 |
| mattermost / mattermost_server | 10.12.0 | 10.12.2 |
| mattermost / mattermost_server | 11.0.0 | 11.0.3 |
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