Axios 0.31.0 Security Patch: Prototype Pollution Chain Exposes Cloud Metadata, Risk of RCE

A critical security update for the widely-used Axios HTTP client library patches a severe vulnerability that creates a dangerous attack chain. The flaw, tracked as CVE-2026-40175, allows a Prototype Pollution vulnerability in any third-party dependency to be escalated into a full-blown security breach. This chain can lead to Remote Code Execution (RCE) or the unrestricted exfiltration of sensitive cloud metadata from affected systems.

The vulnerability stems from a specific "Gadget" attack vector within Axios versions prior to 0.31.0. An attacker who can exploit Prototype Pollution in another library used by an application can leverage this chain to manipulate Axios's behavior. The primary risk is header injection, which can be weaponized to access cloud provider metadata services—like those from AWS, Google Cloud, or Azure—that are typically isolated from application code. This could expose credentials, instance data, and other secrets.

The patch, released in Axios version 0.31.0, is being distributed via automated dependency managers like RenovateBot, which flags the update as addressing a security issue. The disclosure highlights the systemic risk in modern software supply chains, where a vulnerability in a foundational library like Axios can amplify flaws elsewhere in the dependency tree. Developers are under immediate pressure to update from version 0.30.x to eliminate this escalation path and prevent potential cloud infrastructure compromise.