GHSA-356w-63v5-8wf4
Fix: vitejs/vite@175a839GHSA-356w-63v5-8wf4 is a Information Exposure vulnerability in vite. O3 Security confirms whether GHSA-356w-63v5-8wf4 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Vite has an `server.fs.deny` bypass with an invalid `request-target`
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-356w-63v5-8wf4.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
vitenpmDescription
Summary
The contents of arbitrary files can be returned to the browser if the dev server is running on Node or Bun.
Impact
Only apps with the following conditions are affected.
- explicitly exposing the Vite dev server to the network (using --host or server.host config option)
- running the Vite dev server on runtimes that are not Deno (e.g. Node, Bun)
Details
HTTP 1.1 spec (RFC 9112) does not allow # in request-target. Although an attacker can send such a request. For those requests with an invalid request-line (it includes request-target), the spec recommends to reject them with 400 or 301. The same can be said for HTTP 2 (ref1, ref2, ref3).
On Node and Bun, those requests are not rejected internally and is passed to the user land. For those requests, the value of http.IncomingMessage.url contains #. Vite assumed req.url won't contain # when checking server.fs.deny, allowing those kinds of requests to bypass the check.
On Deno, those requests are not rejected internally and is passed to the user land as well. But for those requests, the value of http.IncomingMessage.url did not contain #.
PoC
npm create vite@latest
cd vite-project/
npm install
npm run dev
send request to read /etc/passwd
curl --request-target /@fs/Users/doggy/Desktop/vite-project/#/../../../../../etc/passwd http://127.0.0.1:5173
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | vite | ≥ 6.2.0&&< 6.2.6 | 6.2.6 |
| 📦npm | vite | ≥ 6.1.0&&< 6.1.5 | 6.1.5 |
| 📦npm | vite | ≥ 6.0.0&&< 6.0.15 | 6.0.15 |
| 📦npm | vite | ≥ 5.0.0&&< 5.4.18 | 5.4.18 |
| 📦npm | vite | all versions | 4.5.13 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vite. 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 vite to 6.2.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-356w-63v5-8wf4 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-356w-63v5-8wf4 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-356w-63v5-8wf4. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-356w-63v5-8wf4 in your dependencies?
O3 detects GHSA-356w-63v5-8wf4 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.