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.
References
| Link | Resource |
|---|---|
| https://mattermost.com/security-updates | Vendor Advisory |
Configurations
Configuration 1 (hide)
|
History
03 Dec 2025, 15:17
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Mattermost
Mattermost mattermost Server |
|
| CPE | cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* | |
| References | () https://mattermost.com/security-updates - Vendor Advisory |
27 Nov 2025, 18:15
| Type | Values Removed | Values Added |
|---|---|---|
| Summary | (en) 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. |
27 Nov 2025, 16:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2025-11-27 16:15
Updated : 2025-12-03 15:17
NVD link : CVE-2025-12419
Mitre link : CVE-2025-12419
CVE.ORG link : CVE-2025-12419
JSON object : View
Products Affected
mattermost
- mattermost_server
CWE
CWE-303
Incorrect Implementation of Authentication Algorithm