How to Fix CVE-2026-39365: vite (Bundle Sibling)
*By Sai Kiran Pandrala*
Last verified: 2026-05-25
| Severity | CVSS 6.3, Medium |
|---|---|
| Actively exploited? | No |
| Affected | Vitejs vite (>= 8.0.0, < 8.0.5, >= 7.0.0, < 7.3.2); Vitejs vite-plus (< 0.1.16) |
| Fixed in | Same patched build as CVE-2026-39363 |
| Type (CWE) | CWE-22: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') |
CVE-2026-39365 is a sibling vulnerability in the same Vitejs vite advisory bundle as CVE-2026-39363. The same patched build closes every CVE in the bundle, so the remediation procedure for CVE-2026-39365 matches the primary write-up.
What is different about CVE-2026-39365?
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.
Impact is consistent with the bundle: a security bypass on the affected component. The patched build closes every code path in the advisory in one update.
How to fix CVE-2026-39365
Apply the patched build per the primary write-up: How to Fix CVE-2026-39363.
For a quick check, confirm the running version of vite:
# Confirm the installed version via your package manager
dpkg -l | grep -i vite # Debian/Ubuntu
rpm -qa | grep -i vite # RHEL/CentOS/Rocky
Frequently asked questions
Is CVE-2026-39365 being actively exploited?
Not at the time of writing. It is not listed in CISA's Known Exploited Vulnerabilities catalog. That status can change, so monitor the vendor advisory and the KEV catalog if the system is exposed.
How severe is CVE-2026-39365?
CVSS rates it 6.3 (Medium). Use that score to set your patch priority alongside the other items in your queue.
Do I have to take vite offline to apply the patch?
It depends on the deployment. High-availability or clustered installs can usually patch one node at a time with no full outage. Standalone installs typically need a short restart. Always follow the vendor's documented upgrade steps.
What if my vulnerability scanner still flags CVE-2026-39365 after I patch?
Re-run the scan after a service restart, then confirm the scanner's plugin set is up to date. Some scanners detect by banner version only and lag the official fix metadata by a release.
References
- Official vendor advisory: https://github.com/vitejs/vite/security/advisories/GHSA-4w7w-66w2-5vf9
- NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2026-39365
- CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog
- Primary write-up: How to Fix CVE-2026-39363
*Written by Sai Kiran Pandrala. Last verified 2026-05-25. Part of the Vitejs vite advisory bundle. Full procedure at how-to-fix-cve-2026-39363.*