CVE-2026-44490: axios Prototype Pollution

Vulnerability summary

CVE-2026-44490 is a high (CVSS 8.2) Prototype Pollution vulnerability in axios. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 33% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 11-06-2026
   PublishedVulnerability first disclosed.
2. 11-06-2026
   Last modifiedVulnerability information updated.

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.

• CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.