CVE-2026-44495: Axios: Credential Theft and Response Hijacking via Prototype Pollution Gadget in Config Merge

Synopsis

This is a prototype-pollution gadget vulnerability in the Axios HTTP client library (versions 0.19.0 through 0.31.0 and 1.0.0 through 1.15.1) for Node.js and browser environments. The vulnerability is reachable over the network but requires high attack complexity because a separate prototype-pollution weakness in the same JavaScript process must already be present before Axios can be exploited as a gadget. Successful exploitation gives an attacker the ability to read credentials and sensitive response data, tamper with response handling, and cause limited service disruption. Patched versions (0.31.1 and 1.15.2) are available, and patched-image rebuilds are available on HarborGuard for environments running affected versions.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The affected service must be reachable over the network for an attacker to deliver the initial prototype-pollution vector that this gadget depends on.

• AuthenticationNot required

  No authentication is required; the exploit path does not depend on holding any account or credential against the target service.

• Victim interactionNot required

  No victim interaction is needed; the attacker does not rely on a user clicking a link or taking any manual action.

• Attack complexityDetail

  Attack complexity is high because exploitation requires a separate prototype-pollution vulnerability (or equivalent attacker control over Object.prototype) to already be active in the same JavaScript process before Axios processes a request.

Blast Radius

• An attacker reads credentials, authorization tokens, or sensitive fields embedded in Axios request configs or response bodies.
• An attacker modifies how Axios processes responses by injecting a malicious transformResponse function via the polluted prototype, altering data before it reaches application logic.
• An attacker causes limited disruption to the affected service by injecting invalid config values that break request handling or response parsing.