CVE-2026-22880: Mattermost Mobile

Medium severity, CVSS 6.1. EPSS: 0.1% chance of exploitation in the next 30 days.

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

Affected products

• Mattermost Mattermost Mobile: before 2.37.1 (fixed in 2.37.1)

Published 2026-05-21. Last modified 2026-08-06.