Open-Source Security Intelligence

Know every vulnerability
before it knows you.

DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.

Checkout DevGuardView on GitHub
Search

GHSA-m48g-4wr2-j2h6

MediumCVSS 6.2 / 10
Published Mar 12, 2026·Last modified Mar 14, 2026
Affected Components(0)

No affected components available

Description

Summary

The TinaCMS CLI dev server configures Vite with server.fs.strict: false, which disables Vite's built-in filesystem access restriction. This allows any unauthenticated attacker who can reach the dev server to read arbitrary files on the host system

Details

When running tinacms dev, the CLI starts a Vite dev server configured in: packages/@tinacms/cli/src/next/vite/index.ts

server: {
  host: configManager.config?.build?.host ?? false,
  ...
  fs: {
    strict: false, // Disables Vite's filesystem access restriction
  },
},

TinaCMS middleware only intercepts specific route prefixes (/media/*, /graphql, /altair, /searchIndex). Any request to a path outside these routes falls through to Vite's default static file handler, which will serve the file directly from the absolute path on the filesystem. Additionally, the server enables permissive CORS (cors() with no origin restriction), which may further facilitate browser-based exploitation such as DNS rebinding attacks.

PoC

Prerequisites: TinaCMS CLI dev server running (default port 4001).

  • Read system files directly:
curl http://localhost:4001/etc/passwd
<img width="705" height="332" alt="image" src="https://github.com/user-attachments/assets/6fd0e1c7-a549-40c8-bc81-af9c343f52a0" /> 
curl http://localhost:4001/etc/hostname
<img width="631" height="41" alt="image" src="https://github.com/user-attachments/assets/bd103dc3-d4c3-4774-8007-b55de3fc2a9e" /> Vite resolves and serves the absolute path directly from the filesystem.

Impact

Any developer running tinacms dev in an environment where the dev server port is reachable by an attacker. This includes:

  • Cloud IDEs (GitHub Codespaces, Gitpod) where ports are automatically forwarded and publicly accessible

  • Docker or VM setups with port forwarding configured

  • Misconfigured environments binding to 0.0.0.0 via the build.host config option

  • Systems targeted via DNS rebinding attacks, leveraging the unrestricted CORS policy

  • Local environments with malicious dependencies running on the same machine

An attacker who can reach port 4001 can:

  • Read any file readable by the server process (/etc/passwd, /etc/shadow, SSH private keys)

  • Exfiltrate environment variables and secrets via /proc/self/environ

  • Access cloud credentials and API keys from configuration files

Risk Scores
Base Score
6.2

The vulnerability requires local access to the device to be exploited. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information.

Threat Intelligence
5.7

Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.

EPSS
1.03%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

Related Vulnerabilities

Browse More

Medium severity
Scan your project

Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.

Checkout DevGuard