Last updated: January 12, 2026
An honest security analysis of Fly.io for developers considering it for their projects.
Fly.io is safe for global edge deployments with strong infrastructure (runs Firecracker VMs). 'fly secrets' encrypts credentials. Key difference from Vercel: you manage full Linux containers across 30+ regions. Main concern: multi-region secrets sync must be verified.
Fly.io is ideal for latency-sensitive global apps. The Firecracker VM isolation is enterprise-grade. Unlike Vercel/Netlify (managed serverless), you control the full stack - which means you also own security patching. Use 'fly secrets' for credentials and Private Networking for internal traffic.
Understanding Fly.io security in the context of broader industry trends and research.
of Lovable applications (170 out of 1,645) had exposed user data in the CVE-2025-48757 incident
Source: CVE-2025-48757 security advisory
average cost of a data breach in 2023
Source: IBM Cost of a Data Breach Report 2023
developers using vibe coding platforms like Lovable, Bolt, and Replit
Source: Combined platform statistics 2024-2025
“There's a new kind of coding I call 'vibe coding', where you fully give in to the vibes, embrace exponentials, and forget that the code even exists.”
“Vibe coding your way to a production codebase is clearly risky. Most of the work we do as software engineers involves evolving existing systems, where the quality and understandability of the underlying code is crucial.”
fly secrets encrypts credentials and syncs them across all regions where your app runs. Set with 'fly secrets set KEY=value'. Secrets are injected as environment variables at runtime. Verify deployment with 'fly secrets list' - ensure all regions have the latest values.
Different models: Fly.io gives you full Linux containers (more control, more responsibility). Vercel abstracts infrastructure (less control, managed security). Fly.io's Firecracker isolation is battle-tested. Choose Fly.io for global edge containers; Vercel for managed serverless.
Private Networking creates a WireGuard-encrypted mesh between all your Fly machines globally. Internal traffic uses .internal domains and never touches the public internet. Enable in fly.toml and use internal hostnames for database connections.
Fly Volumes are NOT encrypted at rest by default. If storing sensitive data, encrypt at the application level before writing to Volumes. This is different from managed databases like RDS which encrypt by default.
Don't guess - scan your app and know for certain. VAS checks for all the common security issues in Fly.io applications.