CVE-2026-44492: Axios: shouldBypassProxy does not recognize IPv4-mapped IPv6 addresses, allowing NO_PROXY bypass (incomplete fix for CVE-2025-62718)

Severity: high (CVSS 8.6 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 12.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-06-11 · updated 2026-09-11
Weakness: CWE-918

Description

Axios is a promise based HTTP client for the browser and Node.js. Prior to 0.32.0 and 1.16.0, Axios does not normalise IPv4-mapped IPv6 addresses. When NO_PROXY lists an IPv4 address such as 127.0.0.1 or 169.254.169.254, a request URL using the IPv4-mapped IPv6 form (::ffff:7f00:1, ::ffff:a9fe:a9fe) still routes through the configured proxy. Node.js resolves these addresses to the underlying IPv4 host, so the request reaches the internal service via the proxy rather than being blocked. This vulnerability is fixed in 0.32.0 and 1.16.0.

Affected products

axios: before 0.32.0; from 1.0.0 before 1.16.0 — fixed in 0.32.0, 1.16.0
Npm Axios: from 1.15.0 before 1.16.0; before 0.32.0 — fixed in 1.16.0, 0.32.0

How to fix

Upgrade to a fixed version: axios 0.32.0, 1.16.0; Npm Axios 1.16.0, 0.32.0. Check the vendor advisory for mitigations.

References

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