CVE-2025-12419

critical · 9.9

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.

9.9

CVSS

0.3%

EPSS (exploit prob.)

28th

EPSS percentile

2025-11-27

Published

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Weaknesses

CWE-303

Affected products

Vendor	Product	Affected versions
mattermost	mattermost_server	>= 10.5.0, < 10.5.13
mattermost	mattermost_server	>= 10.11.0, < 10.11.5
mattermost	mattermost_server	>= 10.12.0, < 10.12.2
mattermost	mattermost_server	>= 11.0.0, < 11.0.4

Check a specific version with /api/v1/cve/match.

References

https://mattermost.com/security-updates

Query this programmatically:

curl https://evil-db.io/api/v1/cve/CVE-2025-12419