CVE-2026-101908: axios Prototype Pollution

Vulnerability summary

CVE-2026-101908 is a medium (CVSS 6.9) Prototype Pollution vulnerability in axios. EPSS estimates a 0.41% chance of exploitation in the next 30 days, higher than 34.1% of scored vulnerabilities.

Timeline

1. 28-09-2026
   PublishedVulnerability first disclosed.
2. 28-09-2026
   Last modifiedVulnerability information updated.

Description

Axios is a promise-based HTTP client for the browser and Node.js. From 1.7.0 until 1.20.0, the fetch adapter constructs a Request with sanitized resolvedOptions but then calls fetch with the original fetchOptions. A separate same-process prototype-pollution flaw populates Object.prototype.headers so fetchOptions.headers resolves through inheritance. The inherited fetchOptions.headers value overrides the sanitized Request headers through the second argument to fetch after Request construction. Attacker-controlled request headers can alter authorization, caching, metadata-service access, or application-specific behavior. This issue is fixed in version 1.20.0.

• CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.