{"id":"EUVD-2025-199833","revision":"aff30dbd6f87493e88ed032d59835be6","records":[{"revision":"aff30dbd6f87493e88ed032d59835be6","observedAt":"2026-10-27T21:49:48.23+00:00","statement":{"source":"euvd","id":"EUVD-2025-199833","aliases":["CVE-2025-12421","GHSA-mp6x-97xj-9x62"],"title":"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 …","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":null,"modifiedAt":null,"affected":[],"metrics":[{"system":"EUVD CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","score":9.9,"severity":null}],"references":["https://mattermost.com/security-updates"],"sourceUrl":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2025-199833","license":"ENISA EUVD · source terms and attribution apply","enrichment":{"sourceStatus":null,"weaknesses":[],"productCriteria":[],"sourceDates":{"datePublished":"Nov 27, 2025, 5:47:04 PM","dateUpdated":"Feb 26, 2026, 4:07:25 PM"},"relatedAdvisories":[{"id":"NCSC-2025-0378","title":"Kwetsbaarheden verholpen in Mattermost","vulnerabilityIds":["CVE-2025-12421","CVE-2025-12419"]}],"note":"EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON."},"key":"euvd:EUVD-2025-199833","identifiers":["EUVD-2025-199833","CVE-2025-12421","GHSA-mp6x-97xj-9x62"]},"retained":false,"historicalAffected":[]}],"coverage":[]}