Executive brief
nebula-mesh is a management tool for Slack Nebula virtual private networks. A security flaw allows any user with a standard API key to bypass permission checks and gain full administrative control over the entire system. This could allow an attacker to take over servers, modify firewall rules, or disable other users' access, potentially leading to a complete compromise of the private network.
Technical details
The vulnerability is a missing authorization check (CWE-862) within the `/api/v1/*` route surface. While the Web UI and CA-management endpoints implement proper gates, endpoints for hosts, networks, firewalls, and operators trust the bearer token alone without verifying resource ownership or admin status. An attacker with a low-privileged operator API key can exploit this to mint an admin API key, re-enroll and hijack victim hosts, or perform CRUD operations on any tenant's network resources. The fix in version 0.3.4 introduces uniform authorization gates (e.g., `isActiveAdmin`) across all affected API handlers.
Affected products
- forgekeep nebula-mesh < 0.3.4
Timeline
- 2026-05-20: disclosed: Initial advisory publication
- 2026-05-24: patched: Fix committed to repository
- 2026-07-23: advisory: NVD publication date