CVE-2026-42044

Axios is a promise based HTTP client for the browser and Node.js. From 1.0.0 to before 1.15.2, he Axios library is vulnerable to a Prototype Pollution Gadget attack that allows any Object.prototype pollution in the applications dependency tree to be escalated into surgical, invisible modification of all JSON API responses — including privilege escalation, balance manipulation, and authorization bypass. The default transformResponse function at lib/defaults/index.js:124 calls JSON.parse(data, this.parseReviver), where this is the merged config object. Because parseReviver is not present in Axios defaults, not validated by assertOptions, and not subject to any constraints, a polluted Object.prototype.parseReviver function is called for every key-value pair in every JSON response, allowing the attacker to selectively modify individual values while leaving the rest of the response intact. This vulnerability is fixed in 1.15.2.

Weakness

The product receives input from an upstream component that specifies multiple attributes, properties, or fields that are to be initialized or updated in an object, but it does not properly control which attributes can be modified.

Affected Software

Extended Description

If the object contains attributes that were only intended for internal use, then their unexpected modification could lead to a vulnerability. This weakness is sometimes known by the language-specific mechanisms that make it possible, such as mass assignment, autobinding, or object injection.

Potential Mitigations

• If available, use features of the language or framework that allow specification of allowlists of attributes or fields that are allowed to be modified. If possible, prefer allowlists over denylists.
• For applications written with Ruby on Rails, use the attr_accessible (allowlist) or attr_protected (denylist) macros in each class that may be used in mass assignment.

References

• https://github.com/axios/axios/security/advisories/GHSA-3w6x-2g7m-8v23
• https://github.com/axios/axios/security/advisories/GHSA-3w6x-2g7m-8v23