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.