CVE-2026-22880 MEDIUM

CVE-2026-22880: Mobile SSO authentication flow allows credential theft via malicious server

Vendor Mattermost
Product Mattermost
Weakness CWE-352 · CSRF
Published May 21, 2026
Last update May 21, 2026
View on NVD All CVEs

CVSS base score

6.1/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction Required
Confidentiality High
Integrity None

CVSS vector

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

What the vulnerability does

01Description

Mattermost Mobile Apps versions <=2.37 11.4 2.0.37 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to properly validate the SSO authentication callback origin which allows an attacker controlling a malicious Mattermost server to steal user credentials for a legitimate Mattermost server via relaying the SSO code exchange flow through the mobile application. Mattermost Advisory ID: MMSA-2025-00564

Key dates

02Disclosure timeline

May 21, 2026 CVE published
May 21, 2026 Record updated