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TI-2025-40211 Aliases CVE-2025-65025GHSA-h3mw-4f23-gwpw

esm.sh CDN service has arbitrary file write via tarslip

Priority HIGH 81CWE-22Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub.

Summary

esm.sh is a nobuild content delivery network(CDN) for modern web development. Prior to version 136, the esm.sh CDN service is vulnerable to path traversal during NPM package tarball extraction. An attacker can craft a malicious NPM package containing specially crafted file paths (e.g., package/../../tmp/evil.js). When esm.sh downloads and extracts this package, files may be written to arbitrary locations on the server, escaping the intended extraction directory. This issue has been patched in version 136.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00571 47th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed esm.sh (esm-dev): 136github.com/esm-dev/esm.sh (Go): 0.0.0-20251117232647-9d77b88c3207

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
esm-devesm.shbefore 136136Patch availableCNA
—github.com/esm-dev/esm.sh (Go)before 0.0.0-20251117232647-9d77b88c32070.0.0-20251117232647-9d77b88c3207Patch availableGHSA-h3mw-4f23-gwpw
  • esm.sh Vendoresm-dev Affected before 136 Fixed in 136 Patch available CNA
  • github.com/esm-dev/esm.sh (Go) Vendor— Affected before 0.0.0-20251117232647-9d77b88c3207 Fixed in 0.0.0-20251117232647-9d77b88c3207 Patch available GHSA-h3mw-4f23-gwpw

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:esm:esm.sh:*:*:*:*:*:*:*:*before 136Vulnerableesm-dev
  • cpe:2.3:a:esm:esm.sh:*:*:*:*:*:*:*:* Versions before 136 Vulnerable ·esm-dev

Remediation

  • Fix · CNA esm.sh (esm-dev) Fixed in 136
  • Fix · GHSA-h3mw-4f23-gwpw github.com/esm-dev/esm.sh (Go) Fixed in 0.0.0-20251117232647-9d77b88c3207 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-65025
  2. 2026-10-03 Alias added: GHSA-h3mw-4f23-gwpw

References

Exploit 1

Patch 1

Advisory 1

Other 1

  • TI-2025-32063 esm.sh is vulnerable to full-response SSRF CVSS 4.0HIGH 8.7
  • TI-2025-40212 esm.sh CDN service has JS Template Literal Injection in CSS-to-JavaScript CVSS 3.1CRITICAL 9.6
  • TI-2026-22092 esm.sh has SSRF localhost/private-network bypass in `/http(s)` module route CVSS 3.1HIGH 7.5
  • TI-2026-19038 esm.sh has path traversal in `extractPackageTarball` that enables file writes from malicious packages CVSS 4.0HIGH 7.7

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences