If you discover a security vulnerability in Brig, please report it responsibly.

Do not open a public GitHub issue for security vulnerabilities.

Instead, please use GitHub Security Advisories to report vulnerabilities privately. Include:

1. Description of the vulnerability.
2. Steps to reproduce.
3. Affected versions.
4. Potential impact.

Brig's security model relies on the following boundaries:

• Lima VM: The only hard security boundary protecting macOS from untrusted workloads.
• gVisor (runsc): Defense-in-depth inside the VM. Not a security boundary.
• Per-cell networks: Isolation by network topology.
• Warden proxy: Mandatory egress choke point enforcing network policy.

Vulnerabilities that break these boundaries are considered critical.

1. No east-west traffic between cells.
2. Warden cannot be abused as a gateway.
3. Secrets are observable (exfiltration is detectable), not preventable.
4. macOS state directory is untrusted.
5. gVisor must be active (no silent downgrade).
6. Only Warden may attach to the proxy-external network.
7. No privileged services on cell networks.
8. Cells must be single-homed (one network only).
9. Warden must be running before cells start.