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).
- CVSS 3.1
- 9.9
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - EPSS
- 0.4% chance of exploitation in the next 30 days; higher than 35% of CVEs (scores of 2026-10-25)
- CWE
- CWE-303
- Published
- Modified
- Record from
- the NVD, synced
Affected
- mattermost:mattermost_server
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-mp6x-97xj-9x62 | Go | github.com/mattermost/mattermost/server/v8 | <8.0.0-20251022210333-acda1fb5dd46 | 8.0.0-20251022210333-acda1fb5dd46 |
| GHSA-mp6x-97xj-9x62 | Go | github.com/mattermost/mattermost-server | >=11.0.0 <11.0.3 | 11.0.3 |
| GHSA-mp6x-97xj-9x62 | Go | github.com/mattermost/mattermost-server | >=10.12.0 <10.12.2 | 10.12.2 |
| GHSA-mp6x-97xj-9x62 | Go | github.com/mattermost/mattermost-server | >=10.11.0 <10.11.5 | 10.11.5 |
| GHSA-mp6x-97xj-9x62 | Go | github.com/mattermost/mattermost-server | >=10.5.0 <10.5.13 | 10.5.13 |
| GO-2025-4170 | Go | github.com/mattermost/mattermost-server | all versions | no fix published |
| GO-2025-4170 | Go | github.com/mattermost/mattermost-server/v5 | all versions | no fix published |
| GO-2025-4170 | Go | github.com/mattermost/mattermost-server/v6 | all versions | no fix published |
| GO-2025-4170 | Go | github.com/mattermost/mattermost/server/v8 | <8.0.0-20251022210333-acda1fb5dd46 | 8.0.0-20251022210333-acda1fb5dd46 |