Path Traversal in github.com/esm-dev/esm.sh (CVE-2026-44594)
Summary
Path traversal in github.com/esm-dev/esm.sh (CVE-2026-44594). Confidential information can be exposed externally. Exploitable via browser. Mitigation: upgrade to 0.0.0-20250616164159-0593516c4cfa or later.
Original description
The description as published by the source.
esm.sh is a no-build content delivery network (CDN) for web development. In 137 and earlier, a Local File Inclusion (LFI) vulnerability exists in the esbuild plugin's handling of the browser field in package.json. An attacker can publish an npm package that causes the server to read and return arbitrary files from the host filesystem during the build process.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-44594 has been found in github.com/esm-dev/esm.sh.
Attackers can target a specific entry point like browser over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.5/10.
What to do: upgrade github.com/esm-dev/esm.sh to 0.0.0-20250616164159-0593516c4cfa or later.
If unsure, ask your IT team or search "github.com/esm-dev/esm.sh CVE-2026-44594" on the vendor's site.
CVE-2026-44594 (github.com/esm-dev/esm.sh) — CWE-22 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: browser / OnResolve / sourcesContent
Patched: 0.0.0-20250616164159-0593516c4cfa — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Path traversal (CWE-22) exists in github.com/esm-dev/esm.sh. Attackers reach the vulnerable code path via browser without authentication.
Check the vendor advisory for the affected versions of github.com/esm-dev/esm.sh. Attack surface: browser / OnResolve / sourcesContent.
Severity: High (CVSS 7.5/10). Confidential information can be exposed externally.
Update to 0.0.0-20250616164159-0593516c4cfa.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/esm-dev/esm.sh' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'github.com/esm-dev/esm.sh' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/esm-dev/esm.shを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade github.com/esm-dev/esm.sh to 0.0.0-20250616164159-0593516c4cfaステージング環境で 0.0.0-20250616164159-0593516c4cfa に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- web github.com
- web github.com