high8.7
CVE-2026-44593
esm.sh is a no-build content delivery network (CDN) for web development.
Impact
esm.sh is a no-build content delivery network (CDN) for web development. In 137 and earlier, the legacy router first retrieves a response from legacyServer, parses the incoming request path, and ultimately writes the data to storage via buildStorage.Put. The router concatenates the path components without sanitizing them, producing a storage key. When this key is used, the underlying file system resolves the relative segments and writes the file to the specified path. Thus an attacker can craft a request that writes data to arbitrary locations on the server.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/esm-dev/esm.sh | < 0.0.0-20260508100112-1960055e1d53 | 0.0.0-20260508100112-1960055e1d53 |