ZoomEye finds 756,074 Mattermost hosts exposed online

A ZoomEye query for app="Mattermost" returned 756,074 matching hosts on 2 October 2026. Many deployments may allow self-registration and expose metrics, while conversation history can hold credentials and incident discussions.

• ZoomEye: 756,074 hosts identify as Mattermost
• Some deployments allow self-registration and expose metrics
• Chat history holds bot tokens, attachments and internal system names
• Recommended: disable self-registration and rotate integration tokens