esm.sh is vulnerable to full-response SSRF
Priority HIGH 77CWE-918Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.
Summary
esm.sh is a no-build content delivery network (CDN) for web development. In version 136, esm.sh is vulnerable to a full-response SSRF, allowing an attacker to retrieve information from internal websites through the vulnerability. Version 137 fixes the vulnerability.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00437 38th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed github.com/esm-dev/esm.sh (Go): 0.0.0-20250616164159-0593516c4cfa
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| esm-dev | esm.sh | = 136 | — | No fix listed | CNA |
| — | github.com/esm-dev/esm.sh (Go) | before 0.0.0-20250616164159-0593516c4cfa | 0.0.0-20250616164159-0593516c4cfa | Patch available | GHSA-3c9r-837r-qqm4 |
- esm.sh Vendoresm-dev Affected = 136 Fixed in — No fix listed CNA
- github.com/esm-dev/esm.sh (Go) Vendor— Affected before 0.0.0-20250616164159-0593516c4cfa Fixed in 0.0.0-20250616164159-0593516c4cfa Patch available GHSA-3c9r-837r-qqm4
Remediation
- Fix · GHSA-3c9r-837r-qqm4 github.com/esm-dev/esm.sh (Go) Fixed in 0.0.0-20250616164159-0593516c4cfa Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2025-50180
- 2026-10-03 Alias added: GHSA-3c9r-837r-qqm4
References
Patch 4
- https://github.com/esm-dev/esm.sh/pull/1149
- https://github.com/esm-dev/esm.sh/commit/0593516c4cfab49ad3b4900416a8432ff2e23eb0
- https://github.com/esm-dev/esm.sh/blob/f80ff8c8d58749e77fa964abde468fc61f8bd89e/internal/fetch/fetch.go#L13
- https://github.com/esm-dev/esm.sh/blob/f80ff8c8d58749e77fa964abde468fc61f8bd89e/server/router.go#L511
More esm-dev Esm.sh vulnerabilities
- TI-2025-40211 esm.sh CDN service has arbitrary file write via tarslip CVSS 3.1CRITICAL 9.8
- TI-2025-40212 esm.sh CDN service has JS Template Literal Injection in CSS-to-JavaScript CVSS 3.1CRITICAL 9.6
- TI-2026-22092 esm.sh has SSRF localhost/private-network bypass in `/http(s)` module route CVSS 3.1HIGH 7.5
- TI-2026-19038 esm.sh has path traversal in `extractPackageTarball` that enables file writes from malicious packages CVSS 4.0HIGH 7.7
Sources
- CVE-2025-50180 · CVE Program
- CVE-2025-50180 · NVD
- FIRST EPSS
- GHSA-3c9r-837r-qqm4 · GitHub Advisory Database · CC BY 4.0
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