Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4 fail to verify whether a guest account is deactivated before creating a session in the magic-link token login path, which allows a deactivated guest user to obtain a fully functional session via a magic-link token issued prior to deactivation.. Mattermost Advisory ID: MMSA-2026-00681

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Fixes

Solution

Update Mattermost to versions 11.8.0, 11.7.3, 11.6.5 or higher.


Workaround

No workaround given by the vendor.

References
History

Mon, 13 Jul 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Mon, 13 Jul 2026 09:45:00 +0000

Type Values Removed Values Added
First Time appeared Mattermost
Mattermost mattermost
Vendors & Products Mattermost
Mattermost mattermost

Mon, 13 Jul 2026 08:45:00 +0000

Type Values Removed Values Added
Description Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4 fail to verify whether a guest account is deactivated before creating a session in the magic-link token login path, which allows a deactivated guest user to obtain a fully functional session via a magic-link token issued prior to deactivation.. Mattermost Advisory ID: MMSA-2026-00681
Title Deactivated guest accounts can authenticate via magic-link token in Mattermost REST API login endpoint
Weaknesses CWE-305
References
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published:

Updated: 2026-07-13T13:55:15.448Z

Reserved: 2026-05-26T15:15:14.343Z

Link: CVE-2026-9597

cve-icon Vulnrichment

Updated: 2026-07-13T13:55:11.951Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-07-13T17:30:04Z

Weaknesses