AIKIDO-2026-872099

TL;DR

Request interceptors can replace the merged axios config with a plain object, including a spread clone such as {...config}. That drops the null-prototype container created at merge, so later reads of behavior options walk Object.prototype and treat inherited fields such as adapter, proxy, or transformResponse as trusted config. Class-based replacements and a foreign-realm Object.prototype whose constructor was mutated, deleted, or replaced by an accessor had the same gap. A polluted prototype can therefore hijack the transport or rewrite responses. Version 1.20.0 keeps a safe merged config by identity, snapshots interceptor replacements onto a null prototype, and ignores behavior inherited only from shared or foreign prototypes.