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OpenAdvisories
Medium · 4.3 CVE-2026-18256 EUVD-2026-102749GHSA-mqc4-5px9-95jm

Private team metadata disclosure via the team search API

Published Oct 16, 2026 · Updated Oct 16, 2026 · Assigned by Mattermost

Description

Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to properly restrict private teams from public team search results, which allows an authenticated user without permission to list private teams to disclose the ID, name, and display name of private teams via a modified team search request. Mattermost Advisory ID: MMSA-2026-00748

Affected products

VendorProductAffectedFixed
Mattermost Mattermost 11.10.0 – ≤ 11.10.0, 11.7.0 – ≤ 11.7.9, 11.9.0 – ≤ 11.9.1, 11.8.0 – ≤ 11.8.5 11.11.0

Advisories 1

References