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GHSA-4w7w-66w2-5vf9 — vite

Fix: vitejs/vite#22161

GHSA-4w7w-66w2-5vf9 is a Path Traversal vulnerability in vite. A fix is available for vite — see the affected versions and patch details below.

Vite Vulnerable to Path Traversal in Optimized Deps `.map` Handling

Also known asCVE-2026-39365
Published
Apr 6, 2026
Updated
Sep 10, 2026
Affected
3 pkgs
Patched
3 / 3
Exploits
None indexed
Exploitation data as of Sep 25, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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.
  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
  • A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA’s SSVC triage for GHSA-4w7w-66w2-5vf9.

EPSS Exploitation Probability

via FIRST.org ↗
1.0%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs61th percentile — riskier than 61% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

3 pkgs affected

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.

7Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream
vitenpm
169.3Mdownloads / week

Description

Summary

Any files ending with .map even out side the project can be returned to the browser.

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)
  • have a sensitive content in files ending with .map and the path is predictable

Details

In Vite v7.3.1, the dev server’s handling of .map requests for optimized dependencies resolves file paths and calls readFile without restricting ../ segments in the URL. As a result, it is possible to bypass the server.fs.strict allow list and retrieve .map files located outside the project root, provided they can be parsed as valid source map JSON.

PoC

  1. Create a minimal PoC sourcemap outside the project root
    cat > /tmp/poc.map <<'EOF'
    {"version":3,"file":"x.js","sources":[],"names":[],"mappings":""}
    EOF
    
  2. Start the Vite dev server (example)
    pnpm -C playground/fs-serve dev --host 127.0.0.1 --port 18080
    
  3. Confirm that direct /@fs access is blocked by strict (returns 403) <img width="4004" height="1038" alt="image" src="https://github.com/user-attachments/assets/15a859a8-1dc6-4105-8d58-80527c0dd9ab" />
  4. Inject ../ segments under the optimized deps .map URL prefix to reach /tmp/poc.map <img width="2790" height="846" alt="image" src="https://github.com/user-attachments/assets/5d02957d-2e6a-4c45-9819-3f024e0e81f2" />

Affected Packages

3 total 3 fixed
EcosystemPackageVulnerable rangeFix
📦npmvite≥ 8.0.0&&< 8.0.58.0.5npm install vite@8.0.5
📦npmvite≥ 7.0.0&&< 7.3.27.3.2npm install vite@7.3.2
📦npmviteall versions6.4.2npm install vite@6.4.2

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vite, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update vite to 8.0.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4w7w-66w2-5vf9 is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-4w7w-66w2-5vf9 can be triaged on real exposure rather than presence alone.

Tailored to GHSA-4w7w-66w2-5vf9. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

How to detect GHSA-4w7w-66w2-5vf9

A community-maintained Nuclei template exists for this CVE. You can scan for it directly:

nuclei -id ghsa-4w7w-66w2-5vf9 -u https://target
Template
Vite Dev Server - Path Traversal in Optimized Deps .map Handling
Severity
medium
Impact
An attacker can trigger auto-generated sourcemap responses for files outside the project directory, leaking absolute filesystem paths and potentially reading .map files containing sensitive source code or configuration data.
Remediation
Upgrade Vite to version 8.0.5, 7.3.2, 6.4.2 or later.

Template by ProjectDiscovery nuclei-templates (theamanrawat), MIT licensed. View the full template. Scan only systems you are authorised to test.

Frequently Asked Questions

### Summary Any files ending with `.map` even out side the project can be returned to the browser. ### 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](https://vitejs.dev/config/server-options.html#server-host)) - have a sensitive content in files ending with `.map` and the path is predictable ### Details In Vite v7.3.1, the dev server’s handling of `.map` requests for optimized dependencies resolves file paths and calls `readFile` without restricting `../` segments
O3 Security · Impact-Aware SCA

Is GHSA-4w7w-66w2-5vf9 in your dependencies?

O3 Security finds GHSA-4w7w-66w2-5vf9 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-4w7w-66w2-5vf9: vite | O3 Security