Skip to content
Heist/ feed
MediumFix available

Axios: Prototype-Pollution Gadget in the Default Instance Allows Inherited Object.prototype.method to Override HTTP Method

Type: advisorySource: OSV1 source record

## Summary Axios default-instance requests that omit an explicit method can read an inherited `method` value from `Object.prototype`. If another vulnerability in the same process pollutes `Object.prototype.method`, calls such as `axios.request({ url })` and `axios({ url })` can send a state-changing HTTP method instead of the expected default `GET`. Axios does not create the prototype pollution source. This is a read-side gadget in axios request dispatch. ## Impact In an affected application with a separate prototype-pollution primitive, an attacker can change axios default-instance requests that omit `method` from `GET` to methods such as `DELETE`, `POST`, `PUT`, or `PATCH`. The practical impact depends on the target endpoint and can include unintended writes, deletion, or other state changes. Method aliases such as `axios.get(url)` and requests with an explicit own `method` are not affected by the confirmed method path. ## Affected Functionality Affected: - Default axios instance calls: `axios.request({ url })`. - Callable shorthand: `axios({ url })`. - Requests where no own `config.method` is provided. Not affected in the confirmed method PoC: - `axios.get(url)` and other method aliases. - `axios.request({ url, method: 'GET' })`. - `axios.create().request({ url })` when the created instance defaults are produced by current `mergeConfig()` and do not inherit from `Object.prototype`. ## Technical Details `lib/core/Axios.js` sets the request method with: ```js config.method =

Announced Group revision 1
Original source ↗

GHSA-9fr6-4gfg-395g

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: osv:GHSA-9fr6-4gfg-395g

axios

Source reference: /affected/0/package/name

Affected versions
Not stated in this record
Fixed versions
0.34.0

Source reference: /affected/0/ranges

Prerequisites
Not stated in this record

axios

Source reference: /affected/1/package/name

Affected versions
Not stated in this record
Fixed versions
1.20.0

Source reference: /affected/1/ranges

Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "ranges": [
      {
        "type": "SEMVER",
        "events": [
          {
            "introduced": "0.27.2"
          },
          {
            "fixed": "0.34.0"
          }
        ]
      }
    ],
    "package": {
      "name": "axios",
      "purl": "pkg:npm/axios",
      "ecosystem": "npm"
    },
    "database_specific": {
      "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-9fr6-4gfg-395g/GHSA-9fr6-4gfg-395g.json"
    }
  },
  {
    "ranges": [
      {
        "type": "SEMVER",
        "events": [
          {
            "introduced": "1.0.0"
          },
          {
            "fixed": "1.20.0"
          }
        ]
      }
    ],
    "package": {
      "name": "axios",
      "purl": "pkg:npm/axios",
      "ecosystem": "npm"
    },
    "database_specific": {
      "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-9fr6-4gfg-395g/GHSA-9fr6-4gfg-395g.json"
    }
  }
]
Related CVEs
CVE-2026-101902

Source reference: /aliases

Publisher severity

No explicit severity was provided.

Linked CVE context

These ratings describe the referenced vulnerabilities and products. They are not a severity rating for every application using this dependency.

Event
#37703 · Revision 1
Added to Heist Feed
Publisher date
Read the original announcement