CVE-2025-12419
Mattermost versions 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12, 11.0.x <= 11.0.3 fail to properly validate OAuth state tokens during OpenID Connect authentication which allows an authenticated attacker with team creation privileges to take over a user account via manipulation of authentication data during the OAuth completion flow. This requires email verification to be disabled (default: disabled), OAuth/OpenID Connect to be enabled, and the attacker to control two users in the SSO system with one of them never having logged into Mattermost.
Package Versions Affected
Automatically patch vulnerabilities without upgrading
CVSS Version



Related Resources
References
https://nvd.nist.gov/vuln/detail/CVE-2025-12419, https://github.com/mattermost/mattermost/pull/34296, https://github.com/mattermost/mattermost/commit/15364790cc277cfaa372693d2d5442b87f70fd42, https://github.com/mattermost/mattermost/commit/364c2203de00fe0d8424b6b46d6f0eeb02a2539a, https://github.com/mattermost/mattermost/commit/46b5c436bb3093cc1da3fa2455f93d4c52389eee, https://github.com/mattermost/mattermost/commit/c3f4818afe46a7084740e809708ae22641c76d8d, https://github.com/mattermost/mattermost/commit/d3ed703dc8330684952eb8d49a375bac6ea7b0c6, https://github.com/advisories/GHSA-3x39-62h4-f8j6, https://github.com/mattermost/mattermost, https://mattermost.com/security-updates
