CVE-2026-39363 Vite Affected by Arbitrary File Read via Vite Dev Server WebSocket
An attacker can read arbitrary files on the server by exploiting a missing access control check in the Vite dev server WebSocket interface.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-39363?
CVE-2026-39363 is a high-severity path traversal vulnerability in vitejs vite, published on 7 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Vite is a frontend tooling framework for JavaScript. From 6.0.0 to before 6.4.2, 7.3.2, and 8.0.5, if it is possible to connect to the Vite dev server’s WebSocket without an Origin header, an attacker can invoke fetchModule via the custom WebSocket event vite:invoke and combine file://... with ?raw (or ?inline) to retrieve the contents of arbitrary files on the server as a JavaScript string (e.g., export default "..."). The access control enforced in the HTTP request path (such as server.fs.allow) is not applied to this WebSocket-based execution path. This vulnerability is fixed in 6.4.2, 7.3.2, and 8.0.5.
Which versions are affected by CVE-2026-39363?
6 open source packages ship an affected version, including vite. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
vite npm | From 6.0.0 | 6.4.2 |
vite npm | From 6.0.0 | 6.4.2 |
vite npm | From 7.0.0 | 7.3.2 |
vite npm | From 7.0.0 | 7.3.2 |
vite npm | From 8.0.0 | 8.0.5 |
vite npm | From 8.0.0 | 8.0.5 |
Products include Vitejs Vite, Voidzero Vite\+.
How do I fix CVE-2026-39363?
Upgrade vite to a fixed version for your release line: 6.4.2, 7.3.2 or 8.0.5.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-39363 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39363 exists.
Public exploit code: 1 Nuclei template and 3 proofs of concept on GitHub.
Other vulnerabilities in vitejs vite
- CVE-2025-31125 Vite Vitejs Improper Access Control
- CVE-2026-53571 Vite: `server.fs.deny` bypass on Windows alternate paths
- CVE-2026-39364 Vite has a `server.fs.deny` bypass with queries
- CVE-2024-23331 Vite dev server option `server.fs.deny` can be bypassed when hosted on case-insensitive filesystem
- CVE-2023-34092 Vite Server Options (server.fs.deny) can be bypassed using double forward-slash (//)
Sources
Also known as GHSA-p9ff-h696-f583, MINI-f68f-xwf4-c44x, MINI-gjgf-fc8w-hmwj, MINI-hmgf-hq9g-mjm5, MINI-rf4p-vjh3-5j42, MINI-rgqg-prpf-jq9h and 2 more.