Executive brief
TinaCMS CLI is a command-line tool used by developers to manage content and run local development servers. The dev server disables a critical security feature in Vite (the underlying build tool), allowing anyone who can access the server port to read arbitrary files from the system, including SSH keys, configuration files, and environment variables containing secrets. This risk is especially severe in cloud development environments where the dev server port may be publicly exposed.
Technical details
The vulnerability is an arbitrary file read flaw in the TinaCMS CLI dev server. The root cause is that Vite is configured with `server.fs.strict: false`, which disables filesystem access restrictions that normally protect against directory traversal attacks. The dev server also enables unrestricted CORS, facilitating DNS rebinding attacks. Attack vector is local network access to port 4001 (the default dev server port); no authentication or user interaction is required. An attacker who can reach the dev server can directly request absolute filesystem paths (e.g., `http://localhost:4001/etc/passwd`) and receive the file contents. This is particularly impactful in cloud IDEs and shared environments. The vulnerability affects all versions through 2.1.7; patched in version 2.1.8.
Affected products
- TinaCMS CLI all versions prior to 2.1.8
Timeline
- 2026-03-12: disclosed
- 2026-03-12: patched: Fixed in version 2.1.8