Mattermost, Inc.

Mattermost, Inc. operates a widely deployed team-communication and collaboration platform that encompasses server, desktop, and mobile components, positioning itself as a self-hosted alternative to centralized messaging services and thereby enjoying prominent adoption across enterprises and open-source deployments. The vendor's vulnerability footprint, despite a narrow product portfolio, reflects a top-tier position in the collaboration software landscape and concentrates around authorization, access control, and information-disclosure weaknesses that are characteristic of multi-tenant communication systems handling sensitive user interactions and data. Recurring exposure centers on the core Mattermost Server product and its integration ecosystem, with weakness classes clustering around improper authorization checks, insufficient access-control enforcement, and uncontrolled resource consumption—flaws that can affect communication integrity and system availability in environments where the platform anchors team workflows. Defenders deploying Mattermost should prioritize visibility into access control and permission-enforcement changes, especially across integrations and API boundaries where authorization logic is complex. Current severity, exploitation activity, and exposure counts are shown alongside this summary.