{"id":"GHSA-mp6x-97xj-9x62","revision":"f3e2c8817c9947cab3f8ad4cef36864f","records":[{"revision":"f3e2c8817c9947cab3f8ad4cef36864f","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GHSA-mp6x-97xj-9x62","aliases":["CVE-2025-12421","GO-2025-4170"],"title":"Mattermost fails to to verify the token used during code exchange","description":"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).","state":0,"publishedAt":"2025-11-27T18:30:26+00:00","modifiedAt":"2025-12-15T21:11:10.008786+00:00","affected":[{"ecosystem":"Go","name":"github.com/mattermost/mattermost/server/v8","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"8.0.0-20251022210333-acda1fb5dd46"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"11.0.0"},{"kind":"fixed","version":"11.0.3"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"10.12.0"},{"kind":"fixed","version":"10.12.2"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"10.11.0"},{"kind":"fixed","version":"10.11.5"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"10.5.0"},{"kind":"fixed","version":"10.5.13"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"CRITICAL"}],"references":["https://nvd.nist.gov/vuln/detail/CVE-2025-12421","https://github.com/mattermost/mattermost/commit/5072bbf689a46b3b97b2373f26149f5891396e6b","https://github.com/mattermost/mattermost/commit/acda1fb5dd46a2f46c76ae67012423c760525eaa","https://github.com/mattermost/mattermost/commit/f361e7d75a7ab9df5a2106e1ceb919b94b55e41d","https://github.com/mattermost/mattermost/commit/feb598ed2b7ac3cb78a253b032ad7e4628b0de00","https://github.com/mattermost/mattermost","https://mattermost.com/security-updates"],"sourceUrl":"https://github.com/advisories/GHSA-mp6x-97xj-9x62","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-mp6x-97xj-9x62","identifiers":["GHSA-mp6x-97xj-9x62","CVE-2025-12421","GO-2025-4170"]},"retained":false,"historicalAffected":[]}],"coverage":[]}