High [CVE-2026-67314] Outbound Request Tampering via Prototype Pollution in Basic Auth

axios versions >=1.15.2 and <1.18.0 contain prototype-pollution read-side gadgets in Basic auth subfield handling (lib/adapters/http.js and lib/helpers/resolveConfig.js).

When an application is already affected by a separate prototype-pollution primitive and makes an axios request with an own auth object that omits the username and/or password properties, axios reads the inherited Object.prototype.username and Object.prototype.password values and uses them to construct an outbound 'Authorization: Basic...' header. axios itself does not pollute prototypes.

The practical impact is outbound request tampering: an attacker who controls the polluted prototype values can inject attacker-chosen Basic auth credentials or replace an existing Authorization header. Credential disclosure is only possible under additional application-specific conditions.

A flaw was found in axios. Red Hat severity: Important — CVSS 7.4 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N).

Weakness: CWE-915.

Affected products named by the advisory: Red Hat Advanced Cluster Management for Kubernetes 2.13; Red Hat Advanced Cluster Management for Kubernetes 2.14; Red Hat Ansible Automation Platform 2.1; Red Hat Hardened Images; and 19 more.