Axios is a promise-based HTTP client for the browser and Node.js. From 1.15.2 until 1.20.0, the Node HTTP adapter in lib/adapters/http.js supplies request options without an own createConnection value. A separate same-process prototype-pollution flaw places a function on Object.prototype.createConnection. Node resolves and invokes the inherited createConnection socket factory, allowing the attacker-controlled function to select the transport endpoint. The attacker endpoint can receive request headers and bodies, including credentials, and return attacker-controlled responses while the URL appears legitimate. This issue is fixed in version 1.20.0.