Axios: Prototype-Pollution Gadget in the Default Instance Allows Inherited Object.prototype.method to Override HTTP Method
## 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 =
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.
- Event
- #37703 · Revision 1
- Added to Heist Feed
- Publisher date