Incorrect Implementation of Authentication Algorithm Affecting github.com/mattermost/mattermost/server/channels/api4 package, versions >=10.5.0 <10.5.13>=10.11.0 <10.11.5>=10.12.0 <10.12.2>=11.0.0-alpha.1 <11.0.3
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Test your applications- Snyk IDSNYK-GOLANG-GITHUBCOMMATTERMOSTMATTERMOSTSERVERCHANNELSAPI4-14147542
- published28 Nov 2025
- disclosed27 Nov 2025
- creditdaw10
Introduced: 27 Nov 2025
NewCVE-2025-12421 (opens in a new tab)Common Vulnerabilities and Exposures (CVE) are common identifiers for publicly known security vulnerabilities
Common Weakness Enumeration (CWE) is a category system for software weaknesses
How to fix?
Upgrade github.com/mattermost/mattermost/server/channels/api4 to version 10.5.13, 10.11.5, 10.12.2, 11.0.3 or higher.
Overview
Affected versions of this package are vulnerable to Incorrect Implementation of Authentication Algorithm. An attacker can gain unauthorized access to another user's account by leveraging a specially crafted email address when switching authentication methods and sending a request to the /users/login/sso/code-exchange endpoint.
Note:
This is only exploitable if the ExperimentalEnableAuthenticationTransfer setting is enabled and the RequireEmailVerification setting is disabled.