CVE-2026-39365
CWE-22Published: April 7, 2026· Updated: Apr 8, 2026
Official Description
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.
Technical Analysis
CVE-2026-39365 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
CISA has added CVE-2026-39365 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
CVSS v3.1 Vector Breakdown
Exploit & PoC Resources
All References (1)
Quick Facts
Related CVEs (CWE-22)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-39365 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1