Vulnerability · Published May 28, 2026 · Assigned by GitHub_M
CVE-2026-44594esm.sh: Path Traversal via package.json browser field allows reading arbitrary server files
High 7.5
In plain English
A high-severity path traversal in esm.sh from esm-dev. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/esm-dev/esm.sh | 0.0.0-20250616164159-0593516c4cfa | GO-2026-5620 |
| Go | github.com/esm-dev/esm.sh | 0.0.0-20250616164159-0593516c4cfa | GHSA-rg65-45m7-hq57 |
Affected products (as reported)
Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
References
- https://github.com/esm-dev/esm.sh/security/advisories/GHSA-rg65-45m7-hq57 x_refsource_CONFIRM