CVE-2026-44593
HIGH EPSS 28.1%
Published May 28, 20261mo ago · Modified Jun 17, 20262w ago
8.7 CVSS 4.0
Published May 28, 2026 1mo ago
Last Modified Jun 17, 2026 2w ago
Description
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.
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X
Threat Intelligence
EPSS Exploit Probability
28.1% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 1
CWE-22 Path Traversal Resource Mgmt
References 1
- github.com https://github.com/esm-dev/esm.sh/security/advisories/GHSA-3636-h3vx-6465
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.