Which versions of Vite are affected by EUVD-2026-38303?

Development teams using Vite on Windows face an immediate threat to application secrets and credentials if their development servers are network-accessible.. A patch is available.

Is there a public PoC exploit available for EUVD-2026-38303?

Yes, a public proof-of-concept exploit is available for EUVD-2026-38303. Prioritise patching immediately. EPSS: 0.4%.

How to fix or mitigate EUVD-2026-38303?

Within 24 hours: Audit your organization for Vite development servers on Windows systems, particularly those exposed to network access via --host or server.host; immediately restrict exposed servers to localhost-only binding. Within 7 days: Apply the vendor-released patch to Vite and update development environment policies to prohibit network exposure of development servers. Within 30 days: Enforce localhost-only binding for all development servers organization-wide through configuration standards and implement network segmentation policies.

Vite EUVD-2026-38303

Q: What is the CVSS score of EUVD-2026-38303?

EUVD-2026-38303 has a CVSS 4.0 base score of 8.2 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.4%.

| CVE-2026-53571 HIGH

Path Traversal (CWE-22)

2026-06-15 https://github.com/vitejs/vite

GHSA-fx2h-pf6j-xcff

Path Traversal Node.js Microsoft

8.2

CVSS 4.0 · Vendor: https://github.com/vitejs/vite

Severity by source

Vendor (https://github.com/vitejs/vite) PRIMARY

8.2 HIGH

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

vuln.today AI

5.9 MEDIUM

Network-reachable and unauthenticated, but AC:H reflects the required Windows/NTFS + non-default --host conditions; only confidentiality is impacted (file read).

3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Primary rating from Vendor (https://github.com/vitejs/vite).

CVSS VectorVendor: https://github.com/vitejs/vite

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

Analysis Updated

Jun 22, 2026 - 18:34 vuln.today

v3 (cvss_changed)

Analysis Updated

Jun 22, 2026 - 18:33 vuln.today

v2 (cvss_changed)

Re-analysis Queued

Jun 22, 2026 - 18:23 vuln.today

cvss_changed

CVSS changed

Jun 22, 2026 - 18:23 NVD

8.2 (HIGH)

Source Code Evidence Fetched

Jun 15, 2026 - 17:50 vuln.today

Analysis Generated

Jun 15, 2026 - 17:50 vuln.today

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

34 npm packages depend on vite (30 direct, 4 indirect)
11 npm packages depend on vite-plus (9 direct, 2 indirect)

Ecosystem-wide dependent count for version 8.0.0 and other introduced versions.

DescriptionCVE.org

Summary

The contents of files that are specified by server.fs.deny can be returned to the browser on Windows.

Impact

Only apps that match the following conditions are affected:

explicitly exposes the Vite dev server to the network (using --host or server.host config option)
the sensitive file exists in the allowed directories specified by server.fs.allow
either of:
the sensitive file exists in an NTFS volume
the dev server is running on Windows and the sensitive file exists in a volume that 8.3 short name generation is enabled (it is enabled by default on system volumes)

Details

Vite’s dev server denies direct access to sensitive files through server.fs.deny, including entries such as .env, .env.*, and *.{crt,pem}. However, on Windows, the deny logic does not correctly normalize NTFS ADS path forms before access checks are applied. Because of this, requests such as /.env::$DATA?raw are treated as allowed paths, while Windows resolves them to the original file's default data stream.

Similar to that, Windows allows accessing a file using a different name with the 8.3 short name compatibility feature. Vite did not reject accessing files via them.

PoC

bash

$ npm create vite@latest
$ cd vite-project/
$ npm install
$ npm run dev

Access via browser at http://localhost:5173/.env::$DATA?raw <img width="388" height="129" alt="deecc1315123883cfd0f9c26a002845a" src="https://github.com/user-attachments/assets/895c6012-4e2e-4a35-babb-69bbf3ee7170" />

Example expected result:

/.env::$DATA?raw returns the contents of .env
/tls.pem::$DATA?raw returns the contents of tls.pem

AnalysisAI

Arbitrary file disclosure in Vite's development server on Windows allows remote unauthenticated attackers to read sensitive files (such as .env, *.pem, *.crt) that are nominally protected by the server.fs.deny allowlist. The flaw stems from Windows-specific path-form quirks (NTFS Alternate Data Stream syntax ::$DATA and 8.3 short filename aliases) that bypass deny-list normalization, and publicly available exploit code exists in the GHSA advisory. Only dev servers explicitly exposed to the network via --host/server.host are reachable.

Technical ContextAI

Vite is a popular Node.js-based frontend build tool and development server (pkg:npm/vite, pkg:npm/vite-plus) that serves source files from the project directory during development. The server.fs.deny option implements a denylist intended to block direct HTTP access to sensitive files like .env, .env.*, and *.{crt,pem} within otherwise-allowed directories. This issue is a classic CWE-22 Path Traversal variant: the deny-list matcher operates on the URL-supplied filename string without first canonicalizing Windows-specific alternate path forms. NTFS supports Alternate Data Streams accessed via the filename::$DATA syntax, which the Win32 file APIs resolve back to the file's default data stream, and NTFS also generates legacy 8.3 short names (enabled by default on system volumes) that alias the same underlying file. Vite's deny check sees /.env::$DATA?raw as a non-matching filename and serves it, while the OS resolves it to .env.

RemediationAI

Vendor-released patches are available: upgrade vite to 8.0.16, 7.3.5, or 6.4.3 depending on your major version, and upgrade vite-plus to 0.1.24, per https://github.com/vitejs/vite/security/advisories/GHSA-fx2h-pf6j-xcff. If immediate patching is not possible, remove --host from npm run dev invocations and unset server.host so the dev server binds only to localhost, eliminating remote reachability at the cost of losing LAN/mobile preview access. Additionally, do not store production secrets in .env files inside developer working trees on Windows machines that ever expose the dev server, and on NTFS volumes you may disable 8.3 short-name generation with fsutil 8dot3name set 1 (note: this can break legacy applications that rely on short names). Restricting dev-server access via local firewall rules to trusted source IPs is a useful additional control while you roll out the upgrade.