CVE-2024-36257: Mattermost

Medium severity, CVSS 5.3. EPSS: 0.3% chance of exploitation in the next 30 days.

Mattermost versions 9.5.x <= 9.5.5 and 9.8.0, when using shared channels with multiple remote servers connected, fail to check that the remote server A requesting the server B to update the profile picture of a user is the remote that actually has the user as a local one . This allows a malicious remote A to change the profile images of users that belong to another remote server C that is connected to the server A.

Affected products

• Mattermost Mattermost: from 9.5.0, before 9.5.6 (fixed in 9.5.6); version 9.8.0 only

Published 2024-07-03. Last modified 2026-06-17.