CVE-2026-18256 Private team metadata disclosure via the team search API

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...

CVE-2026-18256

Mattermost versions 11.10.x <= 11.10.0 , 11.7.x <= 11.7.9 , 11.9.x <= 11.9.1 , and 11.8.x