CVE-2026-42033: Axios prototype pollution gadgets in mergeConfig

CVE-2026-42033 · Severity: high · CVSS 7.4 · Published 2026-04-24

Axios is a widely used library for making web requests in Node.js and browser applications. A vulnerability exists where an attacker can exploit a separate flaw in a different part of the application to hijack Axios's internal settings. This allows the attacker to silently intercept sensitive data like login credentials, or modify the data received from web services before the application processes it, potentially leading to unauthorized actions or data theft.

Technologies: Axios, axios (npm). Vendors: Axios, npm.

Quick answers

Is CVE-2026-42033 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-42033 being exploited in the wild.
How severe is CVE-2026-42033?
High severity, with a CVSS score of 7.4, published 24 April 2026.
Which products and versions are affected?
Axios <=1.15.0, <=0.31.0; axios (npm) SEMVER:introduced=1.0.0,fixed=1.15.1.
Is there a fix for CVE-2026-42033?
Yes. axios (npm): upgrade to 1.15.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-42033 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-42033?
Check whether you run Axios or axios (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • axios (npm): upgrade to 1.15.1 or later
    npm install axios@1.15.1

Technical details

Axios fails to use hasOwnProperty guards when reading certain configuration keys such as 'parseReviver' and 'transport' during the mergeConfig process. If an attacker can achieve prototype pollution via a co-dependency (e.g., vulnerable versions of lodash), they can inject malicious functions into Object.prototype. These 'gadgets' allow the attacker to intercept and modify JSON responses via the parseReviver function or completely hijack the HTTP adapter by providing a malicious transport object. This can lead to the exfiltration of request headers, bodies, and credentials. The vulnerability is fixed in versions 1.15.1 and 0.31.1.

Affected products

  • Axios axios <=1.15.0, <=0.31.0

Identifiers

  • CVE-2026-42033
  • GHSA-pf86-5x62-jrwf

Timeline

  • 2026-04-24: disclosed
  • 2026-04-24: advisory
  • 2026-04-24: patched

References

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