CVE-2026-39363 Details.
Vite Dev Server - Arbitrary File Read
Atlas does not check this one. Not a plain web check.
This weakness is not found through ordinary web pages. It needs a different kind of connection to the service. Atlas only runs plain web, DNS and TLS checks, so it does not run this one.
About CVE-2026-39363. What It Means.
Vite dev server exposes the fetchModule method via its WebSocket HMR (Hot Module Replacement) endpoint using the vite-hmr sub-protocol. By connecting to the WebSocket endpoint and sending a crafted vite:invoke custom event that calls fetchModule with a file:// URL (e.g., file:///etc/passwd?raw), an attacker can bypass server.fs.deny restrictions and read arbitrary files from the server filesystem. The vulnerability exists because fetchModule does not enforce the same filesys…
Affected Product. What Is Hit.
The record for CVE-2026-39363 does not name a vendor or product yet.
References. Where To Read More.
FAQ
Common Questions.
Vite Dev Server - Arbitrary File Read. Vite dev server exposes the fetchModule method via its WebSocket HMR (Hot Module Replacement) endpoint using the vite-hmr sub-protocol. By connecting to the WebSocket endpoint and sending a crafted vite:invoke custom event that calls fetchModule with a file:// URL (e.g., file:///etc/passwd?raw), an attacker can bypass server.fs.deny restrictions and read arbitrary files from the server filesystem. The vulnerability exists because fetchModule does not enforce the same filesys…
No. This weakness is not found through ordinary web pages. It needs a different kind of connection to the service. Atlas only runs plain web, DNS and TLS checks, so it does not run this one. The facts about CVE-2026-39363 are on this page, and you can request a demo to see how Brandefense watches your whole external attack surface.
CVE-2026-39363 is not on the CISA Known Exploited Vulnerabilities list at the time of writing, but it is still worth fixing.
Update the affected software to the latest version from the vendor, or follow the vendor's advice to switch off the affected feature. Vendor links are listed on this page when they are known.
This page lists the public facts about CVE-2026-39363. Atlas does not run a check for it, so nothing here says whether a particular site is affected.