CVE-2026-42035: 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 ad...

Description

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.

Metrics

CVSS 3.1

7.4/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS Probability

0.39%

31.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Axios	Axios	< 0.31.1
Axios	Axios	>= 1.0.0, < 1.15.1

References

https://github.com/axios/axios/security/advisories/GHSA-6chq-wfr3-2hj9Exploit, Mitigation, Vendor Advisory
https://github.com/axios/axios/security/advisories/GHSA-6chq-wfr3-2hj9Exploit, Mitigation, Vendor Advisory

Timeline

Published: Apr 24, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-42035?

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.

How severe is CVE-2026-42035?

CVE-2026-42035 has a CVSS score of 7.4/10 (HIGH severity). The EPSS model estimates a 0.39% probability of exploitation in the next 30 days.

How do I fix CVE-2026-42035?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.