CVE-2026-42035 Axios: Header Injection via Prototype Pollution
Attackers can inject arbitrary HTTP headers via prototype pollution gadgets, potentially leading to code execution or security bypasses in applications using Axios.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42035?
CVE-2026-42035 is a high-severity code injection vulnerability in axios, published on 24 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-42035?
4 open source packages ship an affected version, including axios. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
axios npm | All versions | 0.31.1 |
axios npm | All versions | 0.31.1 |
axios npm | From 1.0.0 | 1.15.1 |
axios npm | From 1.0.0 | 1.15.1 |
Products include Axios Axios.
How do I fix CVE-2026-42035?
Upgrade axios to a fixed version for your release line: 0.31.1 or 1.15.1.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-42035 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42035 exists.
Other vulnerabilities in axios
- CVE-2026-44494 Axios: Full Man-in-the-Middle via Prototype Pollution Gadget in `config.proxy`
- CVE-2026-44492 axios's shouldBypassProxy does not recognize IPv4-mapped IPv6 addresses, allowing NO_PROXY bypass (incomplete fix for CVE-2025-62718)
- CVE-2026-67320 axios before 0.33.0 Prototype Pollution via Node HTTP adapter
- CVE-2026-44487 Axios: Proxy-Authorization Credential Leak to Origin Server Across HTTP-to-HTTPS Redirect in Axios Node.js HTTP Adapter
- CVE-2025-27152 Possible SSRF and Credential Leakage via Absolute URL in axios Requests
Sources
Also known as CLEANSTART-2026-WQ60704, CLEANSTART-2026-XK85655, DEBIAN-CVE-2026-42035, ECHO-cf1c-28f4-2ed2, GHSA-6chq-wfr3-2hj9, MINI-2j76-fpmf-h33x and 20 more.