CVE-2025-12419

EUVD-2025-199827
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
MattermostCNA
9.9 CRITICAL
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 24%
Affected Products (NVD)
VendorProductVersion
mattermostmattermost_server
10.5.0 ≤
𝑥
< 10.5.13
mattermostmattermost_server
10.11.0 ≤
𝑥
< 10.11.5
mattermostmattermost_server
10.12.0 ≤
𝑥
< 10.12.2
mattermostmattermost_server
11.0.0 ≤
𝑥
< 11.0.4
𝑥
= Vulnerable software versions
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mattermostmattermost
10.12.0 ≤
𝑥
≤ 10.12.1
CNA
mattermostmattermost
10.11.0 ≤
𝑥
≤ 10.11.4
CNA
mattermostmattermost
10.5.0 ≤
𝑥
≤ 10.5.12
CNA
mattermostmattermost
11.0.0 ≤
𝑥
≤ 11.0.3
CNA
Common Weakness Enumeration
References
https://mattermost.com/security-updates