CVE-2026-112947 Vite: First 4 bytes of files outside of `server.fs` setting is exposed by `?vite-wasm-instance`
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-112947?
CVE-2026-112947 is a medium-severity vulnerability in vitejs vite, published on 20 Oct 2026.
Official description
Vite is a frontend tooling framework for JavaScript. From 8.2.0 until 8.2.4 and 8.3.3, the first 4 bytes of files outside of server.fs setting can be returned to the browser by a request containing ?vite-wasm-instance. Requests containing the ?vite-wasm-instance query are handled by the internal Wasm plugin's load hook. The hook removes the query and reads the resulting path directly from disk, but the server.fs checks were not applied. After reading the file, Vite attempts to parse it as WebAssembly. When that parse fails, Node and deno throws an error that contains the first 4 bytes of the file. This vulnerability is fixed in 8.2.4 and 8.3.3.
Which versions are affected by CVE-2026-112947?
6 open source packages ship an affected version, including vite and vite-plus.
| Package | Affected | Fixed in |
|---|---|---|
vite npm | From 8.2.0 | 8.2.4 |
vite npm | From 8.2.0 | 8.2.4 |
vite npm | From 8.3.0 | 8.3.3 |
vite npm | From 8.3.0 | 8.3.3 |
vite-plus npm | From 0.2.8 | 1.1.0 |
vite-plus npm | From 0.2.8 | 1.1.0 |
How do I fix CVE-2026-112947?
Upgrade vite to a fixed version for your release line: 8.2.4 or 8.3.3.
Is CVE-2026-112947 being exploited?
There is no known exploitation of CVE-2026-112947 in the wild and no public exploit code.
Sources
Also known as ECHO-4beb-4040-cfe3, GHSA-vfpm-58rq-9qcg, UBUNTU-CVE-2026-112947.