Server-Side Request Forgery

esm.sh is vulnerable to Server-Side Request Forgery SSRF. The vulnerability is due to insufficient validation in the /https fetch route, where localhost and internal network protections rely on hostname string checks that can be bypassed using DNS alias domains, allowing attackers to induce...

SUSE CVE-2026-27730

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 /https fetch route. The service tries to block localhost/internal targets, but the validation is based on hostname string checks and can be bypass...

CVE-2026-27730

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 /https fetch route. The service tries to block localhost/internal targets, but the validation is based on hostname string checks and can be bypass...

esm.sh has SSRF localhost/private-network bypass in `/http(s)` module route

Summary An SSRF vulnerability CWE-918 exists in esm.sh’s /https 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 for example, 127.0.0.1.nip.io resolving to 127.0.0.1. This allows a...