Axios is vulnerable to a read‑side prototype‑pollution gadget that allows attacker‑controlled data to be injected into requests made with the library’s bodyless methods. If an attacker has previously polluted Object.prototype, they can cause axios.get(), axios.delete(), axios.head(), or axios.options() to transmit an illicit request body, or cause lower‑level adapters to use attacker‑controlled proxy or URL serialization values. This flaw can lead to unauthorized request modification, potentially exposing sensitive data or enabling downstream abuse, but it does not provide direct code execution or other classic higher‑impact effects.

Any Node.js application using axios prior to version 1.18.0 (and versions prior to 0.33.0) is affected, with the vulnerability manifesting in the high‑level bodyless methods and, for legacy setups, in low‑level adapters and helper paths that accept plain configurations. The flaw is present when Application or a dependency can pollute Object.prototype before axios is called.

The CVSS score of 6.3 indicates a medium severity. Because exploitation requires a prior prototype‑pollution condition or direct manipulation of adapter calls, the likelihood of abuse is moderate to low, and EPSS is not available. The vulnerability is not listed in the KEV catalog. Attackers who can influence the JavaScript runtime environment—such as via a compromised dependency that writes to Object.prototype—could trigger the defect, leading to unintended request bodies or proxy use.