Prototype Pollution in Axios
CVE-2026-101908
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.
Vulnerability class: Prototype Pollution
Published · last modified .
EPSS exploit prediction
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Affected products
- Axios — versions >= 1.7.0, < 1.20.0