CVE-2025-12419
Account takeover on OAuth/OpenID-enabled servers
CVSS Score
9.9
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-303 |
| Vendor | mattermost |
| Product | mattermost |
| Published | Nov 27, 2025 |
| Last Updated | Feb 26, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
Mattermost / Mattermost
10.12.0 ≤ 10.12.1 10.11.0 ≤ 10.11.4 10.5.0 ≤ 10.5.12 11.0.0 ≤ 11.0.3
Credits
daw10