Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to properly validate team membership when searching channels which allows a removed team member to enumerate all public channels within a private team via the channel search API endpoint.. Mattermost Advisory ID: MMSA-2025-00568

Project Subscriptions

No data.

Advisories

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Fixes

Solution

Update Mattermost to versions 11.4.0, 11.3.1, 11.2.3, 10.11.11 or higher.


Workaround

No workaround given by the vendor.

References
History

Mon, 16 Mar 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Mon, 16 Mar 2026 11:45:00 +0000

Type Values Removed Values Added
Description Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to properly validate team membership when searching channels which allows a removed team member to enumerate all public channels within a private team via the channel search API endpoint.. Mattermost Advisory ID: MMSA-2025-00568
Title Unauthorized channel enumeration in private teams after member removal
Weaknesses CWE-862
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: 2026-03-16T13:49:57.631Z

Reserved: 2026-02-13T11:08:09.268Z

Link: CVE-2026-2458

cve-icon Vulnrichment

Updated: 2026-03-16T13:44:13.623Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-03-16T14:19:29.543

Modified: 2026-03-16T14:53:07.390

Link: CVE-2026-2458

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses