CVE-2026-22545 in Mattermost
Summary
by MITRE • 03/16/2026
Mattermost versions 10.11.x <= 10.11.10 fail to validate user's authentication method when processing account auth type switch which allows an authenticated attacker to change account password without confirmation via falsely claiming a different auth provider.. Mattermost Advisory ID: MMSA-2026-00583
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Analysis
by VulDB Data Team • 03/21/2026
This vulnerability exists in Mattermost server versions 10.11.0 through 10.11.10 where the authentication system fails to properly validate the user's authentication method during account authentication type switching operations. The flaw allows an authenticated attacker to exploit a logic error in the authentication flow that enables password changes without proper confirmation mechanisms. This occurs when the system processes requests to switch authentication types without verifying that the user actually possesses valid credentials for the claimed authentication provider, creating a potential vector for unauthorized account compromise.
The technical implementation of this vulnerability stems from insufficient input validation and authentication method verification within the account management subsystem. When a user attempts to switch their authentication type from one provider to another, the system should validate that the user has legitimate access to the target authentication method before allowing the change. However, the current implementation permits the switch operation to proceed even when the attacker cannot demonstrate valid authentication credentials for the claimed provider, effectively allowing password resets or authentication method changes without proper authorization.
From an operational perspective, this vulnerability represents a critical security risk that could enable attackers to gain unauthorized control over user accounts. The impact extends beyond simple password changes as it allows attackers to potentially lock out legitimate users or assume their identity within the Mattermost environment. The vulnerability affects any authenticated user who can access the authentication switching functionality, making it particularly dangerous in environments where multiple authentication methods are supported and users may have varying levels of access privileges.
The flaw aligns with CWE-287 which addresses improper authentication issues, specifically focusing on authentication method switching without proper validation. This vulnerability also maps to ATT&CK technique T1566 which covers credential harvesting through social engineering, as attackers could leverage this weakness to escalate privileges and gain unauthorized access to accounts. Organizations using Mattermost in production environments should immediately evaluate their authentication configurations and consider implementing additional access controls or monitoring mechanisms to detect suspicious authentication switching activities.
Mitigation strategies should include immediate patching of affected Mattermost versions to 10.11.11 or later where the vulnerability has been addressed. Administrators should also implement enhanced monitoring for authentication type switching operations and establish automated alerts for suspicious patterns such as rapid authentication method changes or attempts to switch to authentication providers that do not match the user's current credential profile. Additionally, organizations should review their authentication policies to ensure that account recovery procedures include proper verification steps and that users are educated about the importance of maintaining secure authentication credentials across all supported authentication methods.