Vulnerability-Lookup

GHSA-542G-H47M-68V8

Vulnerability from github – Published: 2026-09-30 15:01 – Updated: 2026-09-30 15:01

Summary

Axios: Denial of Service via Unhandled 'error' Event in HTTP/2 ClientHttp2Session Initialization

Details

Summary

Axios versions with Node.js HTTP/2 support can terminate the caller’s process when a ClientHttp2Session emits an error event that is not handled by axios.

This affects applications that use the Node HTTP adapter with httpVersion: 2. A malicious, unavailable, or non-HTTP/2 endpoint can cause an uncaught exception instead of a normal rejected axios request.

Impact

The impact is denial of service. In affected applications, an attacker who can influence the request destination, or operate the destination server, may be able to crash the Node.js process.

This does not affect default HTTP/1.1 usage, browser XHR/fetch adapters, or applications that do not enable axios HTTP/2 support.

Affected Functionality

Affected path:

Node.js HTTP adapter
httpVersion: 2
HTTP/2 session creation/reuse through Http2Sessions
Network/session failures emitted as ClientHttp2Session error events

Caller-controlled http2Options can make the issue easier to trigger, but passing arbitrary attacker input into axios config is caller-controlled behavior and should not be the primary advisory framing.

Technical Details

Http2Sessions.getSession() creates a session with http2.connect(authority, options) but only registers a close handler. It does not register an error handler on the returned ClientHttp2Session.

When the session emits error, Node treats it as an unhandled EventEmitter error and throws. This can bypass the normal axios Promise rejection path and terminate the process.

Proof of Concept of Attack

import axios from './index.js';

await axios.get('http://127.0.0.1:1/', {
  httpVersion: 2,
  timeout: 1000
});

Expected vulnerable behavior: the process exits with an uncaught ECONNREFUSED session error instead of only rejecting the axios request.

Workarounds

Disable axios HTTP/2 for untrusted or user-influenced destinations and use the default HTTP/1.1 adapter until a fixed release is available. Also avoid passing attacker-controlled values into http2Options; axios config is trusted application input.

Original report

Hi, i'm RelunSec a security researcher working with **InsiteTech.jp** i want let you known, i finded a DoS in axios, to reproduce that, that is the example of a server

const http = require('http');
// Import the local axios version to ensure the patch is active
const axios = require('../../lib/axios.js').default; 
const url = require('url');

// A public HTTP/2 server to make internal requests to.
// This simulates an external service your application might interact with over HTTP/2.
const TARGET_URL = 'https://nghttp2.org/'; 
const PORT = 3000;

const server = http.createServer(async (req, res) => {
  const parsedUrl = url.parse(req.url, true);
  const http2optionId = parsedUrl.query.http2optionId;

  if (!http2optionId) {
  console.warn(`[SERVER] Rejected request: Missing http2optionId parameter`);
  res.writeHead(400, { 'Content-Type': 'text/plain' });
  res.end('Error: Missing http2optionId query parameter. Usage: ?http2optionId=value\n');
  return; 
}

  console.log(`[SERVER] Received request with http2optionId: ${http2optionId}`);

  // Create an Axios instance configured for HTTP/2
  // The 'id' in http2Options makes each session configuration unique.
  const axiosInstance = axios.create({
    baseURL: TARGET_URL,
    httpVersion: 2,
    http2Options: {
      // rejectUnauthorized: false, // Uncomment if targeting a local HTTP/2 server with self-signed cert
      id: http2optionId, // This is the attacker-controlled unique part
    },
    // Adding a short timeout to prevent attacker from waiting too long if target is slow
    timeout: 5000 
  });

  try {
    const response = await axiosInstance.get('/');
    res.writeHead(200, { 'Content-Type': 'text/plain' });
    res.end(`Internal HTTP/2 request successful for ID: ${http2optionId}\nStatus: ${response.status}`);
  } catch (error) {
    // Check for the specific error indicating session limit reached
    if (error.isAxiosError && error.code === axios.AxiosError.ERR_BAD_OPTION_VALUE) {
      console.error(`[SERVER] Internal HTTP/2 request failed for ID: ${http2optionId}: ${error.message}`);
      res.writeHead(500, { 'Content-Type': 'text/plain' });
      res.end(`Internal HTTP/2 request failed for ID: ${http2optionId}: ${error.message}`);
    } else {
      console.error(`[SERVER] Internal HTTP/2 request failed for ID: ${http2optionId}:`, error.message);
      res.writeHead(500, { 'Content-Type': 'text/plain' });
      res.end(`Internal HTTP/2 request failed for ID: ${http2optionId}: Generic error - ${error.message}`);
    }
  }
});

server.listen(PORT, () => {
  console.log(`PoC Server listening on http://localhost:${PORT}`);
  console.log(`Targeting internal HTTP/2 requests to: ${TARGET_URL}`);
  console.log(`Send requests to http://localhost:${PORT}?http2optionId=...`);
  console.log(`Expected behavior with current patch: After ~100 unique http2optionIds, subsequent requests will receive ERR_BAD_OPTION_VALUE.`);
});

i tested all that in latest git version, after starting the server.cjs, to trigger that you just need do

relunsec@relunsec:~/software/axios-1/poc/poc$ curl http://127.0.0.1:3000/?http2optionId=hi
curl: (52) Empty reply from server

that is extremly simple to trigger it confirms a DoS in the HTTP/2 session cache, that needs be patched, the impact is will lead the server crashes and shutdown by an attacker, the server is written properly and no flaws in it and try catch blocks and errors handled however because that is an axios internal error will crash

Severity

8.2 (High)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "axios"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.13.0"
            },
            {
              "fixed": "1.20.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-101901"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-30T15:01:07Z",
    "nvd_published_at": "2026-09-28T18:17:18Z",
    "severity": "HIGH"
  },
  "details": "## Summary\n\nAxios versions with Node.js HTTP/2 support can terminate the caller\u2019s process when a ClientHttp2Session emits an error event that is not handled by axios.\n\nThis affects applications that use the Node HTTP adapter with httpVersion: 2. A malicious, unavailable, or non-HTTP/2 endpoint can cause an uncaught exception instead of a normal rejected axios request.\n\n## Impact\n\nThe impact is denial of service. In affected applications, an attacker who can influence the request destination, or operate the destination server, may be able to crash the Node.js process.\n\nThis does not affect default HTTP/1.1 usage, browser XHR/fetch adapters, or applications that do not enable axios HTTP/2 support.\n\n## Affected Functionality\n\nAffected path:\n\n- Node.js HTTP adapter\n- httpVersion: 2\n- HTTP/2 session creation/reuse through Http2Sessions\n- Network/session failures emitted as ClientHttp2Session error events\n\nCaller-controlled http2Options can make the issue easier to trigger, but passing arbitrary attacker input into axios config is caller-controlled behavior and should not be the primary advisory framing.\n\n## Technical Details\n\nHttp2Sessions.getSession() creates a session with http2.connect(authority, options) but only registers a close handler. It does not register an error handler on the returned ClientHttp2Session.\n\nWhen the session emits error, Node treats it as an unhandled EventEmitter error and throws. This can bypass the normal axios Promise rejection path and terminate the process.\n\n## Proof of Concept of Attack\n```js\nimport axios from \u0027./index.js\u0027;\n\nawait axios.get(\u0027http://127.0.0.1:1/\u0027, {\n  httpVersion: 2,\n  timeout: 1000\n});\n```\n\nExpected vulnerable behavior: the process exits with an uncaught ECONNREFUSED session error instead of only rejecting the axios request.\n\n## Workarounds\n\nDisable axios HTTP/2 for untrusted or user-influenced destinations and use the default HTTP/1.1 adapter until a fixed release is available. Also avoid passing attacker-controlled values into http2Options; axios config is trusted application input.\n\n\u003cdetails\u003e\n  \u003csummary\u003e\u003ch3\u003eOriginal report\u003c/h3\u003e\u003c/summary\u003e\n  \nHi, i\u0027m RelunSec a security researcher working with **InsiteTech.jp**\n\ni want let you known, i finded a DoS in axios, to reproduce that, that is the example of a server\n\n```js\nconst http = require(\u0027http\u0027);\n// Import the local axios version to ensure the patch is active\nconst axios = require(\u0027../../lib/axios.js\u0027).default; \nconst url = require(\u0027url\u0027);\n\n// A public HTTP/2 server to make internal requests to.\n// This simulates an external service your application might interact with over HTTP/2.\nconst TARGET_URL = \u0027https://nghttp2.org/\u0027; \nconst PORT = 3000;\n\nconst server = http.createServer(async (req, res) =\u003e {\n  const parsedUrl = url.parse(req.url, true);\n  const http2optionId = parsedUrl.query.http2optionId;\n\n  if (!http2optionId) {\n  console.warn(`[SERVER] Rejected request: Missing http2optionId parameter`);\n  res.writeHead(400, { \u0027Content-Type\u0027: \u0027text/plain\u0027 });\n  res.end(\u0027Error: Missing http2optionId query parameter. Usage: ?http2optionId=value\\n\u0027);\n  return; \n}\n\n  console.log(`[SERVER] Received request with http2optionId: ${http2optionId}`);\n\n  // Create an Axios instance configured for HTTP/2\n  // The \u0027id\u0027 in http2Options makes each session configuration unique.\n  const axiosInstance = axios.create({\n    baseURL: TARGET_URL,\n    httpVersion: 2,\n    http2Options: {\n      // rejectUnauthorized: false, // Uncomment if targeting a local HTTP/2 server with self-signed cert\n      id: http2optionId, // This is the attacker-controlled unique part\n    },\n    // Adding a short timeout to prevent attacker from waiting too long if target is slow\n    timeout: 5000 \n  });\n\n  try {\n    const response = await axiosInstance.get(\u0027/\u0027);\n    res.writeHead(200, { \u0027Content-Type\u0027: \u0027text/plain\u0027 });\n    res.end(`Internal HTTP/2 request successful for ID: ${http2optionId}\\nStatus: ${response.status}`);\n  } catch (error) {\n    // Check for the specific error indicating session limit reached\n    if (error.isAxiosError \u0026\u0026 error.code === axios.AxiosError.ERR_BAD_OPTION_VALUE) {\n      console.error(`[SERVER] Internal HTTP/2 request failed for ID: ${http2optionId}: ${error.message}`);\n      res.writeHead(500, { \u0027Content-Type\u0027: \u0027text/plain\u0027 });\n      res.end(`Internal HTTP/2 request failed for ID: ${http2optionId}: ${error.message}`);\n    } else {\n      console.error(`[SERVER] Internal HTTP/2 request failed for ID: ${http2optionId}:`, error.message);\n      res.writeHead(500, { \u0027Content-Type\u0027: \u0027text/plain\u0027 });\n      res.end(`Internal HTTP/2 request failed for ID: ${http2optionId}: Generic error - ${error.message}`);\n    }\n  }\n});\n\nserver.listen(PORT, () =\u003e {\n  console.log(`PoC Server listening on http://localhost:${PORT}`);\n  console.log(`Targeting internal HTTP/2 requests to: ${TARGET_URL}`);\n  console.log(`Send requests to http://localhost:${PORT}?http2optionId=...`);\n  console.log(`Expected behavior with current patch: After ~100 unique http2optionIds, subsequent requests will receive ERR_BAD_OPTION_VALUE.`);\n});\n```\n\ni tested all that in latest git version, after starting the server.cjs, to trigger that you just need do\n\n```rust\nrelunsec@relunsec:~/software/axios-1/poc/poc$ curl http://127.0.0.1:3000/?http2optionId=hi\ncurl: (52) Empty reply from server\n```\n\nthat is extremly simple to trigger\n\nit confirms a DoS in the HTTP/2 session cache, that needs be patched, the impact is will lead the server crashes and shutdown by an attacker, the server is written properly and no flaws in it and try catch blocks and errors handled however because that is an axios internal error will crash\n\u003c/details\u003e\n\n---",
  "id": "GHSA-542g-h47m-68v8",
  "modified": "2026-09-30T15:01:07Z",
  "published": "2026-09-30T15:01:07Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/security/advisories/GHSA-542g-h47m-68v8"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-101901"
    },
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/pull/11141"
    },
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/commit/d19040bda7a8be2f82c3c6e1a5bc03917daee39a"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/axios/axios"
    },
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/releases/tag/v1.20.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Axios: Denial of Service via Unhandled \u0027error\u0027 Event in HTTP/2 ClientHttp2Session Initialization"
}

CVE-2026-101901 (GCVE-0-2026-101901)

Vulnerability from cvelistv5 – Published: 2026-09-28 17:16 – Updated: 2026-09-28 17:16

Title

Axios: Denial of Service via Unhandled 'error' Event in HTTP/2 ClientHttp2Session Initialization

Summary

Axios is a promise-based HTTP client for the browser and Node.js. From 1.13.0 until 1.20.0, Http2Sessions does not install adequate error handling for a ClientHttp2Session during Axios HTTP/2 session initialization or reuse. A request uses httpVersion: 2 and the ClientHttp2Session emits an error during session initialization or reuse. The unhandled session error escapes normal Promise rejection handling. The uncaught error can terminate the Node.js process and cause denial of service. This issue is fixed in version 1.20.0.

Severity

8.2 (High)


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

CWE

CWE-400 - Uncontrolled Resource Consumption

Assigner

GitHub_M mitre root Scorecard

References

4 references

URL	Tags
https://github.com/axios/axios/security/advisorie…	x_refsource_CONFIRM
https://github.com/axios/axios/pull/11141	x_refsource_MISC
https://github.com/axios/axios/commit/d19040bda7a…	x_refsource_MISC
https://github.com/axios/axios/releases/tag/v1.20.0	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
axios	axios	Affected: >= 1.13.0, < 1.20.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "axios",
          "vendor": "axios",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 1.13.0, \u003c 1.20.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Axios is a promise-based HTTP client for the browser and Node.js. From 1.13.0 until 1.20.0, Http2Sessions does not install adequate error handling for a ClientHttp2Session during Axios HTTP/2 session initialization or reuse. A request uses httpVersion: 2 and the ClientHttp2Session emits an error during session initialization or reuse. The unhandled session error escapes normal Promise rejection handling. The uncaught error can terminate the Node.js process and cause denial of service. This issue is fixed in version 1.20.0."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 8.2,
            "baseSeverity": "HIGH",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-400",
              "description": "CWE-400: Uncontrolled Resource Consumption",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-28T17:16:21.868Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/axios/axios/security/advisories/GHSA-542g-h47m-68v8",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/axios/axios/security/advisories/GHSA-542g-h47m-68v8"
        },
        {
          "name": "https://github.com/axios/axios/pull/11141",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/axios/axios/pull/11141"
        },
        {
          "name": "https://github.com/axios/axios/commit/d19040bda7a8be2f82c3c6e1a5bc03917daee39a",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/axios/axios/commit/d19040bda7a8be2f82c3c6e1a5bc03917daee39a"
        },
        {
          "name": "https://github.com/axios/axios/releases/tag/v1.20.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/axios/axios/releases/tag/v1.20.0"
        }
      ],
      "source": {
        "advisory": "GHSA-542g-h47m-68v8",
        "discovery": "UNKNOWN"
      },
      "title": "Axios: Denial of Service  via Unhandled \u0027error\u0027 Event in HTTP/2 ClientHttp2Session Initialization"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-101901",
    "datePublished": "2026-09-28T17:16:21.868Z",
    "dateReserved": "2026-09-28T15:55:37.906Z",
    "dateUpdated": "2026-09-28T17:16:21.868Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Confirmed: The vulnerability has been validated from an analyst's perspective.
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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.
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Action not permitted

GHSA-542G-H47M-68V8

Summary

Impact

Affected Functionality

Technical Details

Proof of Concept of Attack

Workarounds

Original report

CVE-2026-101901 (GCVE-0-2026-101901)

Tags

Sightings

Nomenclature

Related by attack behaviour