CVE-2026-44490: Axios: DoS & Header Injection via Prototype Pollution Read-Side Gadgets in axios merge functions

Severity: high (CVSS 8.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-06-11 · updated 2026-06-17
Weakness: CWE-1321

Description

Axios is a promise based HTTP client for the browser and Node.js. Prior to 0.32.0 and 1.16.0, axios exposes two read-side prototype-pollution gadgets. When Object.prototype is polluted by an upstream dependency in the same process (e.g. lodash _.merge / CVE-2018-16487), axios silently picks up the polluted values. (1) lib/utils.js line 406 builds merge()'s accumulator as result = {}, so result[targetKey] (line 414) walks Object.prototype and the polluted bucket's own keys are copied into the merged headers and ride out on the wire. (2) lib/core/mergeConfig.js line 26 builds the hasOwnProperty descriptor as a plain-object literal. Object.defineProperty reads descriptor.get/descriptor.set via the prototype chain, so a polluted Object.prototype.get or Object.prototype.set makes the call throw TypeError synchronously on every axios request. This vulnerability is fixed in 0.32.0 and 1.16.0.

Affected products

axios: before 0.32.0; from 1.0.0 before 1.16.0 — fixed in 0.32.0, 1.16.0
Npm Axios: from 1.0.0 before 1.16.0; before 0.32.0 — fixed in 1.16.0, 0.32.0

How to fix

Upgrade to a fixed version: axios 0.32.0, 1.16.0; Npm Axios 1.16.0, 0.32.0. Check the vendor advisory for mitigations.

References

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