CVE-2026-44594 json
esm.sh: Path Traversal via package.json browser field allows reading arbitrary server files
published 2026-05-12 5 mo ago modified 2026-10-26 13 d ago also GHSA-rg65-45m7-hq57 , GO-2026-5620 , EUVD-2026-32911
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 33%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- go github.com/esm-dev/esm.sh 0.0.0-20250616164159-0593516c4cfa
- govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
opensuse advisories openSUSE-SU-2026:21483-1
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 5 mo ago
Exploit prediction
0.39% chance of exploitation in the next 30 days, higher than 33% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/esm-dev/esm.sh/security/advisories/GHSA-rg65-45m7-hq57 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
| GitHub | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/esm-dev/esm.sh | <0.0.0-20250616164159-0593516c4cfa |
0.0.0-20250616164159-0593516c4cfa |
Affected products
- esm-dev esm.sh
Classification
- Weakness
-
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory
References
-
github.com
/esm-dev/esm.sh/security/advisories/GHSA-rg65-45m7-hq57
exploit, web, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-44594
advisory
-
github.com
/esm-dev/esm.sh
package
-
github.com
/esm-dev/esm.sh/releases/tag/v137
web
Sources
- CVE List CVE-2026-44594
- GitHub Advisory GHSA-rg65-45m7-hq57
- NVD CVE-2026-44594
- OSV GO-2026-5620
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.