CVE-2025-12419 — Incorrect Implementation of Authentication Algorithm in Mattermost Mattermost-server

CWE-303 — Incorrect Implementation of Authentication AlgorithmCWE-287 — Improper Authentication5 documents4 sources
Severity
9.9CRITICALNVD
EPSS
0.1%
top 70.45%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
4
Github.com Mattermost Mattermost-serverGithub.com Mattermost Mattermost Server V8Mattermost Server+1 more
Timeline
PublishedNov 27
Latest updateDec 15

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 S…

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HExploitability: 3.1 | Impact: 6.0

Affected Packages4 packages

▶NVDmattermost/mattermost_server10.5.0 — 10.5.13+3
▶Gogithub.com/mattermost_mattermost-server10.12.0 — 10.12.2+3
▶Gogithub.com/mattermost_mattermost_server_v8< 8.0.0-20251028000919-d3ed703dc833
▶CVEListV5mattermost/mattermost10.12.0 — 10.12.1+3

🔴Vulnerability Details

4
OSV
Mattermost fails to properly validate OAuth state tokens during OpenID Connect authentication in github.com/mattermost/mattermost-server↗2025-12-15
▶
GHSA
Mattermost fails to properly validate OAuth state tokens during OpenID Connect authentication↗2025-11-27
▶
CVEList
Account takeover on OAuth/OpenID-enabled servers↗2025-11-27
▶
OSV
Mattermost fails to properly validate OAuth state tokens during OpenID Connect authentication↗2025-11-27
▶
CVE-2025-12419 — CRITICAL severity | cvebase