Nebula Mesh

nebula-mesh is a self-hosted control plane for Slack Nebula mesh VPN. From version 0.2.0 to before version 0.5.0, when OIDC is enabled, GET /ui/oidc/login is reachable without authentication and is registered outside the Web UI rate-limited auth routes. Every request creates a fresh random OIDC state value and stores it in an in-memory map for 10m. Expired states are swept lazily, but there is no rate limit or maximum live-state cap on the allocation path. An unauthenticated remote client can therefore grow OIDC.states for the full state TTL, bounded by request throughput rather than by configured auth rate limits. This issue has been patched in version 0.5.0.

Published: 2026-09-04T19:41:50.326Z
Updated: 2026-09-09T15:56:02.715Z

nebula-mesh is a self-hosted control plane for Slack Nebula mesh VPN. Prior to version 0.7.1, revocation is the only in-band mechanism that isolates a compromised/offboarded host from a Nebula mesh. Because the blocklist never reaches any peer's config.yml, a Blocked host retains full overlay reachability to every peer under its CA (and internal services on the mesh) for up to 30d (agent) / 365d (mobile). An attacker who exfiltrates host.key+host.crt can run stock slackhq/nebula directly, ignore the agent's 403/410 poll responses, and stay connected after the operator revokes the host. Operator-visible state (UI shows blocked, audit log records it) is misleading. This issue has been patched in version 0.7.1.

Published: 2026-09-04T19:43:28.633Z
Updated: 2026-09-08T12:59:24.096Z