CVE-2026-39365
CVE-2026-39365 is a Path Traversal vulnerability in vite. O3 Security confirms whether CVE-2026-39365 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Vite has a Path Traversal in Optimized Deps `.map` Handling
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
vitenpmDescription
Vite is a frontend tooling framework for JavaScript. From 6.0.0 to before 6.4.2, 7.3.2, and 8.0.5, 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. This vulnerability is fixed in 6.4.2, 7.3.2, and 8.0.5.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | vite | ≥ 8.0.0&&< 8.0.5 | 8.0.5 |
| 📦npm | vite | ≥ 7.0.0&&< 7.3.2 | 7.3.2 |
| 📦npm | vite | all versions | 6.4.2 |
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 8.0.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-39365 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 CVE-2026-39365 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 CVE-2026-39365. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-39365 in your dependencies?
O3 detects CVE-2026-39365 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.