esm.sh is a no-build content delivery network (CDN) for web development. Versions up to and including 137 have an SSRF vulnerability (CWE-918) in esm.sh’s `/http(s)` fetch route. The service tries to block localhost/internal targets, but the validation is based on hostname string checks and can be bypassed using DNS alias domains. This allows an external requester to make the esm.sh server fetch internal localhost services. As of time of publication, no known patched versions exist.
References
| Link | Resource |
|---|---|
| https://github.com/esm-dev/esm.sh/security/advisories/GHSA-p2v6-84h2-5x4r | Exploit Vendor Advisory |
Configurations
History
27 Feb 2026, 17:43
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:a:esm:esm.sh:*:*:*:*:*:*:*:* | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.5 |
| First Time |
Esm
Esm esm.sh |
|
| References | () https://github.com/esm-dev/esm.sh/security/advisories/GHSA-p2v6-84h2-5x4r - Exploit, Vendor Advisory |
25 Feb 2026, 16:23
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-02-25 16:23
Updated : 2026-02-27 17:43
NVD link : CVE-2026-27730
Mitre link : CVE-2026-27730
CVE.ORG link : CVE-2026-27730
JSON object : View
Products Affected
esm
- esm.sh
CWE
CWE-918
Server-Side Request Forgery (SSRF)