Vulnerability-Lookup

GHSA-39W2-RJM5-CHCV

Vulnerability from github – Published: 2026-10-07 20:31 – Updated: 2026-10-07 20:31

Summary

Next.js has information disclosure in development server's Model Context Protocol endpoint

Details

The Next.js development server (next dev) exposes a Model Context Protocol endpoint that does not verify which website a request originates from, allowing a malicious website visited by the developer to read sensitive development data — including the project's location on disk, source code snippets from error reports, the route inventory, and development logs. Only applications run with next dev are affected. Production deployments do not serve this endpoint.

Severity

5.4 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

2.3 (Low)


                  
                    CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "next"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "16.0.0"
            },
            {
              "fixed": "16.3.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-94486"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-346"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-07T20:31:51Z",
    "nvd_published_at": "2026-10-02T16:16:51Z",
    "severity": "LOW"
  },
  "details": "The Next.js development server (`next dev`) exposes a Model Context Protocol endpoint that does not verify which website a request originates from, allowing a malicious website visited by the developer to read sensitive development data \u2014 including the project\u0027s location on disk, source code snippets from error reports, the route inventory, and development logs. Only applications run with `next dev` are affected. Production deployments do not serve this endpoint.",
  "id": "GHSA-39w2-rjm5-chcv",
  "modified": "2026-10-07T20:31:51Z",
  "published": "2026-10-07T20:31:51Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/vercel/next.js/security/advisories/GHSA-39w2-rjm5-chcv"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-94486"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vercel/next.js/commit/2d9f50a409312696145b82b3157aadb6b1fef476"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/vercel/next.js"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vercel/next.js/releases/tag/v16.3.8"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Next.js has information disclosure in development server\u0027s Model Context Protocol endpoint"
}

CVE-2026-94486 (GCVE-0-2026-94486)

Vulnerability from cvelistv5 – Published: 2026-10-02 15:12 – Updated: 2026-10-02 16:20

Title

Next.js: Information disclosure in the Next.js development server's Model Context Protocol endpoint

Summary

Next.js is a React framework for building full-stack web applications. From 16.0.0 until 16.3.8, the next dev development server exposes a Model Context Protocol endpoint without reliably restricting cross-site requests. A malicious website visited by a developer can reach the endpoint and read the project's disk location, source code snippets from error reports, route inventory, and development logs. Production deployments do not serve this endpoint. This issue is fixed in version 16.3.8.

Severity

2.3 (Low)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-02 16:20 UTC

CWE

CWE-346 - Origin Validation Error

Assigner

GitHub_M mitre root Scorecard

References

3 references

URL	Tags
https://github.com/vercel/next.js/security/adviso…	x_refsource_CONFIRM
https://github.com/vercel/next.js/commit/2d9f50a4…	x_refsource_MISC
https://github.com/vercel/next.js/releases/tag/v16.3.8	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
vercel	next.js	Affected: >= 16.0.0, < 16.3.8

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-94486",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-02T16:20:02.218983Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-02T16:20:19.256Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "next.js",
          "vendor": "vercel",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 16.0.0, \u003c 16.3.8"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Next.js is a React framework for building full-stack web applications. From 16.0.0 until 16.3.8, the next dev development server exposes a Model Context Protocol endpoint without reliably restricting cross-site requests. A malicious website visited by a developer can reach the endpoint and read the project\u0027s disk location, source code snippets from error reports, route inventory, and development logs. Production deployments do not serve this endpoint. This issue is fixed in version 16.3.8."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 2.3,
            "baseSeverity": "LOW",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "LOW"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-346",
              "description": "CWE-346: Origin Validation Error",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-02T15:12:31.134Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/vercel/next.js/security/advisories/GHSA-39w2-rjm5-chcv",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/vercel/next.js/security/advisories/GHSA-39w2-rjm5-chcv"
        },
        {
          "name": "https://github.com/vercel/next.js/commit/2d9f50a409312696145b82b3157aadb6b1fef476",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/vercel/next.js/commit/2d9f50a409312696145b82b3157aadb6b1fef476"
        },
        {
          "name": "https://github.com/vercel/next.js/releases/tag/v16.3.8",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/vercel/next.js/releases/tag/v16.3.8"
        }
      ],
      "source": {
        "advisory": "GHSA-39w2-rjm5-chcv",
        "discovery": "UNKNOWN"
      },
      "title": "Next.js: Information disclosure in the Next.js development server\u0027s Model Context Protocol endpoint"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-94486",
    "datePublished": "2026-10-02T15:12:31.134Z",
    "dateReserved": "2026-09-21T17:25:42.292Z",
    "dateUpdated": "2026-10-02T16:20:19.256Z",
    "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.

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.

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GHSA-39W2-RJM5-CHCV

CVE-2026-94486 (GCVE-0-2026-94486)

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