Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to sanitize team member data when returned via API to users without elevated permissions which allows a user without permissions to get data about team members roles via invoking various team API endpoints.. Mattermost Advisory ID: MMSA-2026-00626

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Fixes

Solution

Update Mattermost to versions 11.7.0, 11.6.1, 11.5.4, 11.4.5, 10.11.15 or higher.


Workaround

No workaround given by the vendor.

References
History

Fri, 22 May 2026 13:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Fri, 22 May 2026 13:15:00 +0000

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

Fri, 22 May 2026 11:00:00 +0000

Type Values Removed Values Added
Description Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to sanitize team member data when returned via API to users without elevated permissions which allows a user without permissions to get data about team members roles via invoking various team API endpoints.. Mattermost Advisory ID: MMSA-2026-00626
Title Sanitize team member data returned by API
Weaknesses CWE-200
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published:

Updated: 2026-05-22T12:13:43.868Z

Reserved: 2026-03-06T09:40:10.820Z

Link: CVE-2026-3636

cve-icon Vulnrichment

Updated: 2026-05-22T12:13:39.934Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-22T13:00:13Z

Weaknesses