GHSA-5C9X-8GCM-MPGX

Vulnerability from github – Published: 2026-05-05 00:33 – Updated: 2026-05-05 00:33
VLAI?
Summary
Axios' HTTP adapter-streamed uploads bypass maxBodyLength when maxRedirects: 0
Details

Summary

For stream request bodies, maxBodyLength is bypassed when maxRedirects is set to 0 (native http/https transport path). Oversized streamed uploads are sent fully even when the caller sets strict body limits.

Details

Relevant flow in lib/adapters/http.js: - 556-564: maxBodyLength check applies only to buffered/non-stream data. - 681-682: maxRedirects === 0 selects native http/https transport. - 694-699: options.maxBodyLength is set, but native transport does not enforce it. - 925-945: stream is piped directly to socket (data.pipe(req)) with no Axios byte counting.

This creates a path-specific bypass for streamed uploads.

### PoC

Environment:

  • Axios main at commit f7a4ee2
  • Node v24.2.0

Steps: 1. Start an HTTP server that counts uploaded bytes and returns {received}. 2. Send a 2 MiB Readable stream with: - adapter: 'http' - maxBodyLength: 1024 - maxRedirects: 0

Observed: - Request succeeds; server reports received: 2097152.

Control checks: - Same stream with default/nonzero redirects: rejected with ERR_FR_MAX_BODY_LENGTH_EXCEEDED. - Buffered body with maxRedirects: 0: rejected with ERR_BAD_REQUEST.

### Impact Type: DoS / uncontrolled upstream upload / resource exhaustion. Impacted: Node.js services using streamed request bodies with maxBodyLength expecting hard enforcement, especially when following Axios guidance to use maxRedirects: 0 for streams.

Severity ?
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "axios"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.0.0"
            },
            {
              "fixed": "1.15.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 0.31.0"
      },
      "package": {
        "ecosystem": "npm",
        "name": "axios"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.31.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-42034"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-05T00:33:25Z",
    "nvd_published_at": "2026-04-24T18:16:30Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nFor stream request bodies, maxBodyLength is bypassed when maxRedirects is set to 0 (native http/https transport path). Oversized streamed uploads are sent fully even when the caller sets strict body limits.\n\n### Details\n\nRelevant flow in lib/adapters/http.js:\n  - 556-564: maxBodyLength check applies only to buffered/non-stream data.\n  - 681-682: maxRedirects === 0 selects native http/https transport.\n  - 694-699: options.maxBodyLength is set, but native transport does not enforce it.\n  - 925-945: stream is piped directly to socket (data.pipe(req)) with no Axios byte counting.\n\nThis creates a path-specific bypass for streamed uploads.\n\n  ### PoC\n\nEnvironment:\n\n  - Axios main at commit f7a4ee2\n  - Node v24.2.0\n\n  Steps:\n  1. Start an HTTP server that counts uploaded bytes and returns {received}.\n  2. Send a 2 MiB Readable stream with:\n      - adapter: \u0027http\u0027\n      - maxBodyLength: 1024\n      - maxRedirects: 0\n\n  Observed:\n  - Request succeeds; server reports received: 2097152.\n\n  Control checks:\n  - Same stream with default/nonzero redirects: rejected with ERR_FR_MAX_BODY_LENGTH_EXCEEDED.\n  - Buffered body with maxRedirects: 0: rejected with ERR_BAD_REQUEST.\n\n  ### Impact\nType: DoS / uncontrolled upstream upload / resource exhaustion.\nImpacted: Node.js services using streamed request bodies with maxBodyLength expecting hard enforcement, especially when following Axios guidance to use maxRedirects: 0 for streams.",
  "id": "GHSA-5c9x-8gcm-mpgx",
  "modified": "2026-05-05T00:33:25Z",
  "published": "2026-05-05T00:33:25Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/security/advisories/GHSA-5c9x-8gcm-mpgx"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42034"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/axios/axios"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Axios\u0027 HTTP adapter-streamed uploads bypass maxBodyLength when maxRedirects: 0"
}


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