CVE-2024-42000: Mattermost Server

Medium severity, CVSS 4.3. EPSS: 0.3% chance of exploitation in the next 30 days.

Mattermost versions 9.10.x <= 9.10.2, 9.11.x <= 9.11.1, 9.5.x <= 9.5.9 and 10.0.x <= 10.0.0 fail to properly authorize the requests to /api/v4/channels  which allows a User or System Manager, with "Read Groups" permission but with no access for channels to retrieve details about private channels that they were not a member of by sending a request to /api/v4/channels.

Affected products

• Mattermost Mattermost Server: from 9.5.0, before 9.5.10 (fixed in 9.5.10); from 9.10.0, before 9.10.3 (fixed in 9.10.3); from 9.11.0, before 9.11.2 (fixed in 9.11.2); version 10.0.0 only

Published 2024-11-09. Last modified 2026-06-17.