Mattermost versions 11.8.x <= 11.8.2, 11.7.x <= 11.7.6, 10.11.x <= 10.11.21 fail to restrict channel member role assignment to channel-scoped roles which allows a channel administrator to gain additional channel permissions via the channel member roles API.. Mattermost Advisory ID: MMSA-2026-00697

Project Subscriptions

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Advisories

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Fixes

Solution

Update Mattermost to versions 11.9.0, 11.8.3, 11.7.7, 10.11.22 or higher.


Workaround

No workaround given by the vendor.

References
History

Mon, 17 Aug 2026 14:30:00 +0000

Type Values Removed Values Added
Description Mattermost versions 11.8.x <= 11.8.2, 11.7.x <= 11.7.6, 10.11.x <= 10.11.21 fail to restrict channel member role assignment to channel-scoped roles which allows a channel administrator to gain additional channel permissions via the channel member roles API.. Mattermost Advisory ID: MMSA-2026-00697
Title Channel member roles accept out-of-scope roles
Weaknesses CWE-863
References
Metrics cvssV3_1

{'score': 6.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published:

Updated: 2026-08-17T14:22:43.940Z

Reserved: 2026-07-17T09:45:24.899Z

Link: CVE-2026-16048

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

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Weaknesses