PT-2026-42432 · Mattermost · Mattermost

Doyensec · Published 2026-05-21 · Updated 2026-05-21 · CVE-2026-22880

NVD

CVSS v3.1

6.1

Medium

Base vector

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

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

Fix

CSRF

Weakness Enumeration

CWE-352

Related Identifiers

CVE-2026-22880

Affected Products

Mattermost

References · 2

• https://nvd.nist.gov/vuln/detail/CVE-2026-22880 · Security Note
• https://mattermost.com/security-updates · Vendor Advisory