GHSA-gcfj-64vw-6mp9: Axios Node HTTP adapter can use an inherited proxy after interceptor config cloning

Summary Axios’ Node.js HTTP adapter can route requests through an attacker-controlled proxy when Object.prototype.proxy is polluted and request configuration is materialized as a regular object before dispatch. Recent axios releases harden merged request config by creating a null-prototype object. However, request interceptors run after that merge and may return a replacement config. A common immutable interceptor pattern such as {...config} or Object.assign({}, config) converts the hardened config back into a normal object. Axios then dispatches that object without re-hardening it, and the Node HTTP adapter reads config.proxy through the prototype chain. Impact In a Node.js deployment using the HTTP adapter, an attacker who can trigger prototype pollution elsewhere in the process can route affected HTTP requests through an attacker-controlled proxy. The highest confirmed impact is for plaintext HTTP requests. The proxy can observe explicit Authorization headers, axios-generated Basic auth from config.auth, request method, absolute URL, Host, and request body content. The proxy can also return its own response to axios for the affected request. This does not establish browser impact. It also does not establish HTTPS header or body disclosure under normal TLS validation. Affected Functionality Affected functionality is limited to axios requests that use the Node.js HTTP adapter, including default Node usage when the HTTP adapter is selected and explicit adapter: 'http' usage. The relevant configuration path is config.proxy in the Node HTTP adapter. The hardened-bypass path requires a request interceptor such as: api.interceptors.request.use((config) => ({ ...config, headers: { ...config.headers, 'X-App': 'demo' } })); Unaffected or mitigating conditions include browser adapters, the Node fetch adapter, no polluted Object.prototype.proxy, an own proxy: false or safe own proxy value on the config, and hardened releases where interceptors return the original