{"id":"CVE-2025-12421","revision":"141fe2f4adc2469ab0fde925a62f0442","records":[{"revision":"141fe2f4adc2469ab0fde925a62f0442","observedAt":"2026-10-25T01:17:23.283+00:00","statement":{"source":"nvd","id":"CVE-2025-12421","aliases":[],"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":"2025-11-27T18:15:46.223+00:00","modifiedAt":"2026-10-19T13:10:00.11+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · responsibledisclosure@mattermost.com · Secondary","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","score":9.9,"severity":"CRITICAL"}],"references":["https://mattermost.com/security-updates"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-12421","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Analyzed","weaknesses":["CWE-303"],"productCriteria":["cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*"],"sourceDates":{"published":"2025-11-27T18:15:46.223","lastModified":"2026-10-19T13:10:00.110"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2025-12421","identifiers":["CVE-2025-12421"]},"retained":false,"historicalAffected":[]}],"coverage":[]}