Vulnerabilities/

esbuild allows arbitrary file read when running the development server on Windows

Severity:
Low

Description

The development server contains a path traversal vulnerability on Windows when serving files from servedir.

Due to the use of path.Clean() (which only normalizes forward-slash / separators) instead of a Windows-aware path normalization function, it is possible to craft requests using backslashes (\) that bypass the intended directory containment logic.

Recommendation

Update the esbuild package to the latest compatible version. Followings are version details:

References

Related Issues

Tags:
npm
esbuild
Anything's wrong? Let us know Last updated on June 12, 2026