Vite is a frontend tooling framework for javascript. The Vite dev server option `server.fs.deny` can be bypassed on case-insensitive file systems using case-augmented versions of filenames. Notably this affects servers hosted on Windows. This bypass is similar to CVE-2023-34092 -- with surface area reduced to hosts having case-insensitive filesystems. Since `picomatch` defaults to case-sensitive glob matching, but the file server doesn't discriminate; a blacklist bypass is possible. By requesting raw filesystem paths using augmented casing, the matcher derived from `config.server.fs.deny` fails to block access to sensitive files. This issue has been addressed in vite@5.0.12, vite@4.5.2, vite@3.2.8, and vite@2.9.17. Users are advised to upgrade. Users unable to upgrade should restrict access to dev servers.

Vite provides frontend tooling. Prior to versions 2.9.16, 3.2.7, 4.0.5, 4.1.5, 4.2.3, and 4.3.9, Vite Server Options (`server.fs.deny`) can be bypassed using double forward-slash (//) allows any unauthenticated user to read file from the Vite root-path of the application including the default `fs.deny` settings (`['.env', '.env.*', '*.{crt,pem}']`). Only users explicitly exposing the Vite dev server to the network (using `--host` or `server.host` config option) are affected, and only files in the immediate Vite project root folder could be exposed. This issue is fixed in vite@4.3.9, vite@4.2.3, vite@4.1.5, vite@4.0.5, vite@3.2.7, and vite@2.9.16.