Vulnerability · Published Aug 1, 2026 · Assigned by VulnCheck
CVE-2026-67319axios before 0.33.0 Prototype Pollution via nested option objects
Medium 6.3
In plain English
A medium-severity prototype pollution in axios from axios. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
axios before 0.33.0 (and 1.x before 1.18.0) can consume inherited properties from nested request option objects when the JavaScript process's Object.prototype has already been polluted by another component. While the top-level merged config uses a null prototype, nested plain objects such as auth and paramsSerializer are cloned into ordinary objects and read without own-property checks. When an application passes placeholder nested objects such as auth: {} or paramsSerializer: {}, inherited username/password values can cause silent injection of an Authorization: Basic header, and inherited encode/serialize values can alter query-string serialization (full serializer replacement requires a function-valued pollution primitive). This is exploitable only in the presence of pre-existing prototype pollution.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | node-axios | no fix listed | DEBIAN-CVE-2026-67319 |
| Debian:13 | node-axios | no fix listed | DEBIAN-CVE-2026-67319 |
| Debian:14 | node-axios | 1.18.0-1 | DEBIAN-CVE-2026-67319 |
| npm | axios | 0.33.0 | GHSA-7q8q-rj6j-mhjq |
| npm | axios | 1.18.0 | GHSA-7q8q-rj6j-mhjq |
Affected products (as reported)
Weakness: CWE-1321 · Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N
References
- GitHub Security Advisory (GHSA-7q8q-rj6j-mhjq) vendor-advisory
- VulnCheck Advisory: axios before 0.33.0 Prototype Pollution via nested option objects third-party-advisory