CVE-2025-12419

CRITICAL

9.9

Description

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.

CVE Details

CVSS v3.1 Score9.9

SeverityCRITICAL

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

Attack VectorNETWORK

ComplexityLOW

Privileges RequiredLOW

User InteractionNONE

Published11/27/2025

Last Modified12/3/2025

Sourcenvd

Honeypot Sightings0

Affected Products

mattermost:mattermost_server

Weaknesses (CWE)

CWE-303

References

https://mattermost.com/security-updates(responsibledisclosure@mattermost.com)

IOC Correlations

No correlations recorded

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