PT-2025-48273 · Mattermost · Mattermost

Daw10 · Published 2025-10-28 · Updated 2026-03-13 · CVE-2025-12419

Positive Technologies (AI Summary)

CVSS v3.1

9.9

Critical

Base vector

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

Name of the Vulnerable Software and Affected Versions Mattermost versions 10.5.x through 10.5.12 Mattermost versions 10.11.x through 10.11.4 Mattermost versions 10.12.x through 10.12.1 Mattermost versions 11.0.x through 11.0.3

Description The Mattermost application contains a flaw in the implementation of its authentication algorithm. This issue allows an authenticated attacker with team creation or admin privileges to take over any user account by manipulating authentication data during the OAuth completion flow. The issue stems from improper validation of OAuth state tokens during OpenID Connect authentication. This requires email verification to be disabled and OAuth/OpenID Connect to be enabled. The attacker must control two users in the SSO system, with one of them never having logged into Mattermost.

Recommendations Mattermost versions 10.5.x through 10.5.12: Update to a newer, fixed version. Mattermost versions 10.11.x through 10.11.4: Update to a newer, fixed version. Mattermost versions 10.12.x through 10.12.1: Update to a newer, fixed version. Mattermost versions 11.0.x through 11.0.3: Update to a newer, fixed version.

Fix

Weakness Enumeration

CWE-303

Related Identifiers

BDU:2025-15205

CVE-2025-12419

GHSA-3X39-62H4-F8J6

GO-2025-4168

SUSE-SU-2026:0037-1

Affected Products

Mattermost

References · 103

• https://mattermost.com/security-updates · Vendor Advisory
• https://osv.dev/vulnerability/GO-2025-4168 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2026:0037-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2025-12419 · Security Note
• https://bdu.fstec.ru/vul/2025-15205 · Security Note
• https://osv.dev/vulnerability/CVE-2025-12419 · Vendor Advisory
• https://github.com/mattermost/mattermost/commit/15364790cc277cfaa372693d2d5442b87f70fd42 · Note
• https://github.com/mattermost/mattermost/commit/c3f4818afe46a7084740e809708ae22641c76d8d · Note
• https://github.com/mattermost/mattermost/commit/46b5c436bb3093cc1da3fa2455f93d4c52389eee · Note
• https://github.com/mattermost/mattermost/commit/d3ed703dc8330684952eb8d49a375bac6ea7b0c6 · Note
• https://github.com/mattermost/mattermost/commit/364c2203de00fe0d8424b6b46d6f0eeb02a2539a · Note
• https://github.com/mattermost/mattermost/pull/34296 · Note
• https://suse.com/security/cve/CVE-2025-68941 · Note
• https://suse.com/security/cve/CVE-2025-67508 · Note
• https://suse.com/security/cve/CVE-2025-10543 · Note