vulntracker.iovulntracker.io
© 2026 vulntracker.io

CVE-2026-44593

esm.sh: Legacy Route Path Traversal Can Lead to RCE

HIGH
8.7
CVSS Score
Published: May 28, 2026 at 02:44 PM UTC
Updated: October 26, 2026 at 11:10 AM UTC
1 product affected across 1 vendorEsm.sh

Using esm.sh by esm-dev?

Get instant alerts when new vulnerabilities affect esm.sh - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Start FreeSign In
Severity
HIGH8.7
Exploit prediction
EPSS 0.4%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

x_refsource_CONFIRM
Source: cverecord
https://github.com/esm-dev/esm.sh/security/advisories/GHSA-3636-h3vx-6465

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.7HIGHGitHub_M
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-22

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Create accountSign in
Free plan, no card