Executive brief
Nebula-mesh is a tool used for managing network overlays. A security flaw was identified where operator session tokens—the digital keys used to maintain a logged-in session—were stored in the database in plain text. If an attacker gains access to database backups or snapshots, they can use these tokens to impersonate legitimate administrators and take full control of the system without needing a password.
Technical details
A vulnerability in nebula-mesh (specifically within the operator session management logic) results in session tokens being stored in plaintext in the 'operator_sessions' table. The session token, a 32-byte random hex value, is used as a primary key and is sent via cookies for authentication. An attacker with read access to the database—via SQL injection, insecure backups, or file system access—can retrieve these tokens to bypass authentication and hijack active operator sessions. The root cause is the lack of hashing for session tokens, unlike API keys and enrollment tokens in the same application. This issue is addressed in version 0.3.8 by implementing SHA-256 hashing for session tokens at rest.
Affected products
- forgekeep nebula-mesh <= 0.3.7
Timeline
- 2026-06-04: disclosed: Initial report and commit fix
- 2026-07-14: advisory: GitHub Advisory published
- 2026-07-14: patched: Version 0.3.8 released
References
- https://github.com/forgekeep/nebula-mesh/security/advisories/GHSA-q4vm-pq3q-8wgq
- https://github.com/forgekeep/nebula-mesh/commit/7cb01bab281ded557f8b6c81dab5f48d4c10182e
- https://github.com/forgekeep/nebula-mesh/releases/tag/v0.3.8
- https://api.github.com/repos/forgekeep/nebula-mesh/security-advisories/GHSA-q4vm-pq3q-8wgq