How severe is GHSA-4pfg-2mw5-f8jx?

No CVSS score has been assigned to GHSA-4pfg-2mw5-f8jx yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-4pfg-2mw5-f8jx?

GHSA-4pfg-2mw5-f8jx affects the following packages: @cloudflare/vite-plugin (npm). Ecosystems affected: npm.

How do I fix GHSA-4pfg-2mw5-f8jx?

Update @cloudflare/vite-plugin to 1.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4pfg-2mw5-f8jx is resolved across your whole dependency graph.

How do I detect GHSA-4pfg-2mw5-f8jx in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @cloudflare/vite-plugin. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-4pfg-2mw5-f8jx if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-4pfg-2mw5-f8jx?

O3 pinpoints whether GHSA-4pfg-2mw5-f8jx is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-4pfg-2mw5-f8jx actively exploited in the wild?

No public exploit code has been indexed for GHSA-4pfg-2mw5-f8jx yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-4pfg-2mw5-f8jx?

GHSA-4pfg-2mw5-f8jx has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 28th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-4pfg-2mw5-f8jx?

GHSA-4pfg-2mw5-f8jx is classified as Information Exposure (CWE-200). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-4pfg-2mw5-f8jx published, and has it been updated?

GHSA-4pfg-2mw5-f8jx was published on July 8, 2025 and was last updated on September 22, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

GHSA-4pfg-2mw5-f8jx

Cloudflare Vite plugin exposes secrets over the built-in dev server

Also known asCVE-2025-59427

Published

Jul 8, 2025

Updated

Sep 22, 2025

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk28th percentile+0.27%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.

@cloudflare/vite-pluginnpm

4.1Mdownloads / week

Description

Summary

Note: originally posted on H1 but closed. Cross-posting over to here in abundance of caution instead of a public issue.

When utilising the Cloudflare Vite plugin in its default configuration, all files are exposed by the local dev server, including files in the root directory that contain secret information such as:

.env
.dev.vars

PoC

Create a Workers project that utilises the @cloudflare/vite-plugin. For example:
- npm create cloudflare@latest - select Framework Starter -> React
Add any secret files to test if they're accessible. echo foobar=secret > .dev.vars for example
Run npm run dev to start the dev server (after running npm ci if necessary to install dependencies) and then hit the following to expose information:

curl http://localhost:5173/.env may expose any secrets in this file curl http://localhost:5173/.dev.vars may expose any secrets in this file curl http://localhost:5173/package.json may expose dependencies used by the project, potentially leading to other vulnerabilities curl http://localhost:5173/README.md may expose internal documentation

Impact

If the vite dev server is exposed on a public network, such as when a user simply uses wrangler to serve their application and doesn't publish to Cloudflare in production, an attacker may be able to acquire secrets that the user doesn't wish to be exposed.

Another common scenario where this could happen is when sharing previews of an application using cloudflared. npm run dev -> share preview with cloudflared -> now all secrets are exposed to the public internet.

Exposing via vite is possible via:

npm run dev -- -- --host 0.0.0.0

The default configuration has no reason to expose information outside of the configured assets directory.

Example:

curl http://somehost/.env may expose secrets curl http://somehost/.dev.vars may expose secrets curl http://somehost/package.json may expose dependencies used by the project, potentially leading to other vulnerabilities curl http://somehost/README.md may expose internal documentation

etc.

Information disclosure to anyone on the same network, or if the dev server is exposed such as via cloudflared as explored here: https://github.com/cloudflare/workers-sdk/discussions/3455#discussioncomment-6165773

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@cloudflare/vite-plugin`	all versions	1.6.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @cloudflare/vite-plugin. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update @cloudflare/vite-plugin to 1.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4pfg-2mw5-f8jx is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-4pfg-2mw5-f8jx is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-4pfg-2mw5-f8jx. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary Note: [originally posted on H1](https://hackerone.com/reports/3117837) but closed. Cross-posting over to here in abundance of caution instead of a public issue. When utilising the Cloudflare Vite plugin in its default configuration, all files are exposed by the local dev server, including files in the root directory that contain secret information such as: - `.env` - `.dev.vars` ### PoC 1. Create a Workers project that utilises the `@cloudflare/vite-plugin`. For example: - `npm create cloudflare@latest` - select Framework Starter -> React 2. Add any secret files to test if t

O3 Security · Impact-Aware SCA

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