CVE-2026-44594

esm.sh: Path Traversal via package.json browser field allows reading arbitrary server files

esm.sh is a no-build content delivery network (CDN) for web development. In 137 and earlier, a Local File Inclusion (LFI) vulnerability exists in the esbuild plugin's handling of the browser field in package.json. An attacker can publish an npm package that causes the server to read and return arbitrary files from the host filesystem during the build process.

Affected

esm-dev · esm.sh

CVSS v3.1 GITHUB

7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

0.48% chance of exploitation in the next 30 days, 40th percentile

Published

2026-05-28

Proof-of-concept exploits (1)

• advisories/GHSA-rg65-45m7-hq57

References

• CVE Record
• NVD entry