Fly.io Security Checklist
Last updated: January 12, 2026
Use this checklist to ensure your Fly.io application is secure before launch. 2 critical items require immediate attention.
Why This Security Checklist Matters
Security checklists serve as systematic guides for identifying vulnerabilities that might otherwise be overlooked during rapid development cycles. For Fly.io applications specifically, this checklist addresses the most common security gaps that emerge when using AI-assisted development workflows.
Research from multiple security organizations indicates that approximately 80% of AI-built applications contain at least one exploitable vulnerability at launch. The vulnerabilities are often predictable—they follow patterns that this checklist is designed to catch. By systematically reviewing each item, you significantly reduce the risk of launching an insecure application.
Unlike generic security checklists, this guide focuses specifically on vulnerabilities prevalent in Fly.io applications. Each item has been prioritized based on real-world attack patterns and the potential impact of exploitation. Critical items should be addressed before any production deployment.
Critical Priority
Critical items can lead to complete application compromise, data breaches, or unauthorized access to all user accounts. These must be addressed before deploying to production. Attackers actively scan for these vulnerabilities.
High Priority
High priority items represent significant security risks that could allow unauthorized access to sensitive data or functionality. While not immediately catastrophic, these vulnerabilities should be fixed as soon as possible.
Medium/Low Priority
Medium and low priority items strengthen your overall security posture. While they may not be immediately exploitable, addressing them prevents attack chains and defense-in-depth gaps.
Manual vs Automated Security Checking
While manual security reviews are thorough, they're time-consuming and prone to human error. Automated scanning catches common vulnerabilities instantly, freeing you to focus on business logic and complex security decisions.
Items VAS Automates
- Exposed API keys and secrets in JavaScript bundles
- HTTP security header configuration
- Supabase RLS policy testing
- Firebase Security Rules validation
- Cookie security attributes
Manual Review Still Required
- Business logic vulnerabilities
- Custom authentication implementations
- Access control logic in API routes
- Data validation requirements
- Third-party integration security
Secrets Management
Use fly secrets for all credentials
Set secrets with 'fly secrets set' - never commit to git
Scope secrets per environment
Use different secrets for staging and production apps
Rotate secrets periodically
Regularly rotate API keys and passwords
Review secret access
Check which team members can view secrets
Network Security
Use private networking
Keep databases and internal services on Fly.io private network
Configure proper firewall rules
Limit which ports are exposed publicly
Use WireGuard for secure access
Connect to private services via Fly.io WireGuard
Enable TLS termination
AutoLet Fly.io handle TLS at the edge
Container Security
Use minimal base images
Smaller images have fewer vulnerabilities
Scan images for vulnerabilities
Run security scans on container images
Don't run as root
Configure Dockerfile to run as non-root user
Keep images updated
Regularly rebuild with updated base images
Deployment
Configure health checks
Set up health checks for reliable deployments
Use rolling deployments
Avoid downtime with rolling deployment strategy
Set resource limits
Configure memory and CPU limits
Monitor deployment logs
Review logs for errors and security issues
Don't Check Manually
VAS automatically checks 1 of these 16 items. Get instant results with detailed remediation guidance.
Run Automated Security ScanFrequently Asked Questions
What's the difference between critical and high priority items?
Critical items represent immediate security risks that could lead to data breach if not addressed - like missing database access controls or exposed secrets. High priority items are important but typically require an additional vulnerability to exploit.
Can I skip low priority items?
Low priority items provide defense-in-depth but aren't immediate risks. Address all critical and high items before launch. Low items can be added post-launch, but shouldn't be ignored entirely - they protect against edge cases and future vulnerabilities.
How often should I re-run this checklist?
Re-run after major feature additions, authentication changes, or new database tables. Set up automated scanning with VAS to catch regressions. Many teams integrate security scans into their CI/CD pipeline for continuous verification.
What does 'Auto-Scanned' mean on checklist items?
Items marked 'Auto-Scanned' can be automatically verified by VAS. Instead of manually checking each item, run a VAS scan to instantly verify these items against your deployed application. Non-automated items require manual verification.