CVE-2026-42035: Axios

High severity, CVSS 7.4. EPSS: 0.4% chance of exploitation in the next 30 days.

Axios is a promise based HTTP client for the browser and Node.js. Prior to 1.15.1 and 0.31.1, a prototype pollution gadget exists in the Axios HTTP adapter (lib/adapters/http.js) that allows an attacker to inject arbitrary HTTP headers into outgoing requests. The vulnerability exploits duck-type checking of the data payload, where if Object.prototype is polluted with getHeaders, append, pipe, on, once, and Symbol.toStringTag, Axios misidentifies any plain object payload as a FormData instance and calls the attacker-controlled getHeaders() function, merging the returned headers into the outgoing request. The vulnerable code resides exclusively in lib/adapters/http.js. The prototype pollution source does not need to originate from Axios itself — any prototype pollution primitive in any dependency in the application's dependency tree is sufficient to trigger this gadget. This vulnerability is fixed in 1.15.1 and 0.31.1.

Affected products

• Axios Axios: before 0.31.1 (fixed in 0.31.1); from 1.0.0, before 1.15.1 (fixed in 1.15.1)

Published 2026-04-24. Last modified 2026-06-17.