CVE-2026-22880

Mobile SSO authentication flow allows credential theft via malicious server

Published May 21, 2026 CVSS 3.1 · 6.1 Medium EPSS < 1% KEV · Not listed
Description
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

Remediation

Vendor Solution

Update Mattermost Mobile Apps to versions 2.38.0, 11.5.0, 2.37.1.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher.

Tracking

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Advisories

No advisories available
References
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Mattermost
Mattermost mattermost
Vendors & Products Mattermost
Mattermost mattermost
Type Values Removed Values Added
Description 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
Title Mobile SSO authentication flow allows credential theft via malicious server
Weaknesses CWE-352
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Mattermost
Published
Updated
May 21, 2026, 12:39 PM
Reserved
Feb 23, 2026, 10:07 PM
Status
Analyzed
Published
May 21, 2026, 9:16 AM
Modified
Aug 6, 2026, 3:42 PM