GHSA-MP6X-97XJ-9X62 Mattermost fails to to verify the token used during code exchange

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...

CVE-2025-12421

Mattermost suffers an authentication-tampering vulnerability (CVE-2025-12421) where the token used during code exchange is not verified to originate from the same authentication flow. Affected versions include 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, and 10.5.x