CVE-2026-44492: Axios Axios's ShouldBypassProxy Does Not Recognize Vulnerability

HIGH
Advisory Identifier: GHSA-pjwm-pj3p-43mv
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CVSS 8.6
CWE-289 CWE-918
Published
Advisory Summary

CVE-2026-44492 is a HIGH (CVSS 8.6) axios's shouldbypassproxy does not recognize vulnerability (CWE-289: Authentication Bypass by Alternate Name) affecting Axios libraries in the npm ecosystem. The issue involves axios's shouldbypassproxy does not recognize ipv4-mapped ipv6 addresses, allowing no_proxy bypass (incomplete fix for cve-2025-62718). Remediation is available by upgrading affected packages to version 1.16.0, 0.32.0.

CVE-2026-44492 at a Glance

CVE Identifier CVE-2026-44492
GHSA Identifier GHSA-pjwm-pj3p-43mv
Severity HIGH
CVSS v3.1 Base Score 8.6
CWE Classification CWE-289: Authentication Bypass by Alternate Name
Affected Product Axios
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 8.6

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-44492

To remediate this vulnerability, upgrade all affected Axios dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

axios fixed: 1.16.0 
npm install axios@1.16.0
axios fixed: 0.32.0 
npm install axios@0.32.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls axios

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-44492, inspect your project dependencies using npm:

npm ls axios

Analyze the terminal output to locate any version of Axios in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.16.0), your application is affected.

Note: The npm ls axios command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & RFC 5280 Specification

Under RFC 5280 specifications for X.509 certificates, the Name Constraints extension defines a namespace within which all subsequent subject names in a certification path must be located. Constraints apply to various name forms including directory names, IP addresses, rfc822Name (email addresses), and uniformResourceIdentifier (URI) entries. Specifically, during certificate path validation, affected versions of Axios failed to properly normalize or enforce boundary checks when domain names contained trailing dot (.) characters. Because domain names with a trailing dot signify fully qualified domain names (FQDNs), this omission allowed non-conforming certificates to be improperly validated as compliant with the defined name constraints.

Source Advisory Statement

### Summary shouldBypassProxy, introduced in v1.15.0 to fix CVE-2025-62718, 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. ### Details lib/helpers/shouldBypassProxy.js (v1.15.0): ```javascript const LOOPBACK_ADDRESSES = new Set(['localhost', '127.0.0.1', '::1']); const isLoopback = (host) => LOOPBACK_ADDRESSES.has(host); // normalizeNoProxyHost strips brackets and trailing dots, but not ::ffff: prefix return hostname === entryHost || (isLoopback(hostname) && isLoopback(entryHost)); ``` The WHATWG URL parser canonicalises `http://[::ffff:127.0.0.1]/` to hostname `[::ffff:7f00:1]`. After bracket-stripping: `::ffff:7f00:1`. This string does not match 127.0.0.1 in NO_PROXY and is not in LOOPBACK_ADDRESSES, so shouldBypassProxy returns false and the proxy is used. proxy-from-env (called before shouldBypassProxy) has the same gap - it does not equate ::ffff:7f00:1 with 127.0.0.1 - so neither layer catches the bypass. ### PoC ```javascript // NO_PROXY=127.0.0.1,localhost,::1 HTTP_PROXY=http://attacker:8080 import shouldBypassProxy from 'axios/lib/helpers/shouldBypassProxy.js'; // All three should return true (bypass proxy). Only the first two do. console.log(shouldBypassProxy('http://127.0.0.1/')); // true [OK] console.log(shouldBypassProxy('http://[::1]/')); // true [OK] console.log(shouldBypassProxy('http://[::ffff:127.0.0.1]/')); // false <- bypass console.log(shouldBypassProxy('http://[::ffff:7f00:1]/')); // false <- bypass ``` Node.js routes ::ffff:7f00:1 to 127.0.0.1: ``` // net.connect({ host: '::ffff:7f00:1', port: 80 }) reaches a service // bound to 127.0.0.1:80 — confirmed on Node.js v24, Linux and macOS. ``` Cloud metadata SSRF: ::ffff:a9fe:a9fe = ::ffff:169.254.169.254. If NO_PROXY=169.254.169.254 is set to block IMDS access, a request to http://[::ffff:a9fe:a9fe]/latest/meta-data/ bypasses it. #### Fix Canonicalise IPv4-mapped IPv6 in normalizeNoProxyHost before any comparison: ```javascript const ipv4MappedDotted = /^::ffff:(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})$/i; const ipv4MappedHex = /^::ffff:([0-9a-f]{1,4}):([0-9a-f]{1,4})$/i; function hexToIPv4(a, b) { const hi = parseInt(a, 16), lo = parseInt(b, 16); return `${hi >> 8}.${hi & 0xff}.${lo >> 8}.${lo & 0xff}`; } const normalizeNoProxyHost = (hostname) => { if (!hostname) return hostname; if (hostname[0] === '[' && hostname.at(-1) === ']') hostname = hostname.slice(1, -1); hostname = hostname.replace(/\.+$/, '').toLowerCase(); let m; if ((m = hostname.match(ipv4MappedDotted))) return m[1]; if ((m = hostname.match(ipv4MappedHex))) return hexToIPv4(m[1], m[2]); return hostname; }; ``` ### Impact Any application that sets NO_PROXY to exclude internal or metadata endpoints and uses an HTTP/HTTPS proxy can have those exclusions bypassed by a URL using IPv4-mapped IPv6 notation. The attacker must control the request URL. In cloud environments with instance metadata services, this can lead to credential exfiltration.

CVE-2026-44492 Affected Axios Versions

2 component(s)
Fixed Versions:
1.16.00.32.0
Product / Package Ecosystem Affected Versions Fixed Version
axios
npm/axios
npm
≥ 1.15.0
< 1.16.0
1.16.0
axios
npm/axios
npm
< 0.32.0
0.32.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/axios/axios/security/advisories/GHSA-pjwm-pj3p-43mv
NVD — CVE-2026-44492 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-44492
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36611
NVD — CVE-2026-44492 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-62718
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36754
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36820
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36882
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36883
access.redhat.com/errata/rhsa-2026:40... WEB
https://access.redhat.com/errata/RHSA-2026:40119
access.redhat.com/errata/rhsa-2026:40... WEB
https://access.redhat.com/errata/RHSA-2026:40138
access.redhat.com/errata/rhsa-2026:40... WEB
https://access.redhat.com/errata/RHSA-2026:40262
access.redhat.com/errata/rhsa-2026:41... WEB
https://access.redhat.com/errata/RHSA-2026:41031
access.redhat.com/errata/rhsa-2026:41... WEB
https://access.redhat.com/errata/RHSA-2026:41055
access.redhat.com/errata/rhsa-2026:41... WEB
https://access.redhat.com/errata/RHSA-2026:41064
access.redhat.com/errata/rhsa-2026:41... WEB
https://access.redhat.com/errata/RHSA-2026:41066
Axios Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2026-44492
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2487938
Axios Source Repository REPOSITORY
https://github.com/axios/axios
Axios Security Information SECURITY
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44492.json
access.redhat.com/errata/rhsa-2026:20... WEB
https://access.redhat.com/errata/RHSA-2026:20889
access.redhat.com/errata/rhsa-2026:20... WEB
https://access.redhat.com/errata/RHSA-2026:20938
access.redhat.com/errata/rhsa-2026:26... WEB
https://access.redhat.com/errata/RHSA-2026:26234
access.redhat.com/errata/rhsa-2026:27... WEB
https://access.redhat.com/errata/RHSA-2026:27044
access.redhat.com/errata/rhsa-2026:27... WEB
https://access.redhat.com/errata/RHSA-2026:27063
access.redhat.com/errata/rhsa-2026:28... WEB
https://access.redhat.com/errata/RHSA-2026:28964
access.redhat.com/errata/rhsa-2026:29... WEB
https://access.redhat.com/errata/RHSA-2026:29082
access.redhat.com/errata/rhsa-2026:29... WEB
https://access.redhat.com/errata/RHSA-2026:29197
access.redhat.com/errata/rhsa-2026:30... WEB
https://access.redhat.com/errata/RHSA-2026:30650
access.redhat.com/errata/rhsa-2026:30... WEB
https://access.redhat.com/errata/RHSA-2026:30651
access.redhat.com/errata/rhsa-2026:33... WEB
https://access.redhat.com/errata/RHSA-2026:33005
access.redhat.com/errata/rhsa-2026:33... WEB
https://access.redhat.com/errata/RHSA-2026:33155
access.redhat.com/errata/rhsa-2026:33... WEB
https://access.redhat.com/errata/RHSA-2026:33160
access.redhat.com/errata/rhsa-2026:33... WEB
https://access.redhat.com/errata/RHSA-2026:33163
access.redhat.com/errata/rhsa-2026:33... WEB
https://access.redhat.com/errata/RHSA-2026:33173
access.redhat.com/errata/rhsa-2026:33... WEB
https://access.redhat.com/errata/RHSA-2026:33183
access.redhat.com/errata/rhsa-2026:33... WEB
https://access.redhat.com/errata/RHSA-2026:33574
access.redhat.com/errata/rhsa-2026:34... WEB
https://access.redhat.com/errata/RHSA-2026:34766
access.redhat.com/errata/rhsa-2026:36... WEB
https://access.redhat.com/errata/RHSA-2026:36108

Frequently Asked Questions

What is CVE-2026-44492?
CVE-2026-44492 is a security vulnerability in Axios involving axios's shouldBypassProxy does not recognize IPv4-mapped IPv6 addresses, allowing NO_PROXY bypass (incomplete fix for CVE-2025-62718) under CWE-289: Authentication Bypass by Alternate Name.
Which Axios versions are affected?
Affected versions include releases prior to 1.16.0, 0.32.0 across affected packages: axios.
What version fixes CVE-2026-44492?
Upgrading to 1.16.0, 0.32.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is axios affected?
Yes, axios is affected in releases prior to 1.16.0, 0.32.0. Upgrade your dependency to 1.16.0, 0.32.0 or later.
What is the CVSS score of CVE-2026-44492?
CVE-2026-44492 has a CVSS v3.1 base score of 8.6 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N.
What CWE is associated with CVE-2026-44492?
CVE-2026-44492 is classified under CWE-289: Authentication Bypass by Alternate Name (The product performs authentication based on the name of a resource being accessed, or the name of the actor performing the access, but it does not properly check all possible names for that resource or actor.).
How can I check npm dependencies for CVE-2026-44492?
Run the dependency tree command: 'npm ls axios'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-pjwm-pj3p-43mv",
  "modified" : "2026-07-20T12:33:05Z",
  "published" : "2026-05-29T15:59:30Z",
  "aliases" : [ "CVE-2026-44492" ],
  "summary" : "axios's shouldBypassProxy does not recognize IPv4-mapped IPv6 addresses, allowing NO_PROXY bypass (incomplete fix for CVE-2025-62718)",
  "details" : "### Summary\nshouldBypassProxy, introduced in v1.15.0 to fix CVE-2025-62718, 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.\n\n### Details\nlib/helpers/shouldBypassProxy.js (v1.15.0):                                                                                                                                   \n\n```javascript                                                                                                                                                                              \n  const LOOPBACK_ADDRESSES = new Set(['localhost', '127.0.0.1', '::1']);                                                                                                      \n  const isLoopback = (host) => LOOPBACK_ADDRESSES.has(host);                                                                                                                    \n                                                                                                                                                                                \n  // normalizeNoProxyHost strips brackets and trailing dots, but not ::ffff: prefix                                                                                             \n  return hostname === entryHost || (isLoopback(hostname) && isLoopback(entryHost));                                                                                             \n```\n                                                                                                                                                                                \nThe WHATWG URL parser canonicalises `http://[::ffff:127.0.0.1]/` to hostname `[::ffff:7f00:1]`. After bracket-stripping: `::ffff:7f00:1`. This string does not match 127.0.0.1 in NO_PROXY and is not in LOOPBACK_ADDRESSES, so shouldBypassProxy returns false and the proxy is used.  proxy-from-env (called before shouldBypassProxy) has the same gap - it does not equate ::ffff:7f00:1 with 127.0.0.1 - so neither layer catches the bypass.\n\n### PoC\n```javascript\n\n// NO_PROXY=127.0.0.1,localhost,::1  HTTP_PROXY=http://attacker:8080\nimport shouldBypassProxy from 'axios/lib/helpers/shouldBypassProxy.js';                                                                                                       \n                                                                                                                                                                              \n// All three should return true (bypass proxy). Only the first two do.                                                                                                        \nconsole.log(shouldBypassProxy('http://127.0.0.1/'));          // true  [OK]                                                                                                     \nconsole.log(shouldBypassProxy('http://[::1]/'));               // true  [OK]                                                                                                     \nconsole.log(shouldBypassProxy('http://[::ffff:127.0.0.1]/')); // false <- bypass                                                                                             \nconsole.log(shouldBypassProxy('http://[::ffff:7f00:1]/'));     // false <- bypass\n\n```                                                                                              \n                                                                                                                                                                              \nNode.js routes ::ffff:7f00:1 to 127.0.0.1:                                                                                                                                    \n\n```                                                                                                                                                                              \n// net.connect({ host: '::ffff:7f00:1', port: 80 }) reaches a service                                                                                                       \n// bound to 127.0.0.1:80 — confirmed on Node.js v24, Linux and macOS.                                                                                                         \n```                                                                                                                                                                              \nCloud metadata SSRF: ::ffff:a9fe:a9fe = ::ffff:169.254.169.254. If NO_PROXY=169.254.169.254 is set to block IMDS access, a request to http://[::ffff:a9fe:a9fe]/latest/meta-data/ bypasses it.                                                                                                                      \n                                                                                                                                                                            \n#### Fix                                                                                                                                                                           \n                                                                                                                                                                            \nCanonicalise IPv4-mapped IPv6 in normalizeNoProxyHost before any comparison:                                                                                                  \n \n ```javascript                                                                                                                                                                           \nconst ipv4MappedDotted = /^::ffff:(\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3})$/i;                                                                                                    \nconst ipv4MappedHex    = /^::ffff:([0-9a-f]{1,4}):([0-9a-f]{1,4})$/i;                                                                                                         \n                                                                                                                                                                              \nfunction hexToIPv4(a, b) {                                                                                                                                                    \n  const hi = parseInt(a, 16), lo = parseInt(b, 16);                                                                                                                           \n  return `${hi >> 8}.${hi & 0xff}.${lo >> 8}.${lo & 0xff}`;                                                                                                                   \n}                                                                                                                                                                             \n                                                                                                                                                                              \nconst normalizeNoProxyHost = (hostname) => {                                                                                                                                  \n  if (!hostname) return hostname;                                                                                                                                           \n  if (hostname[0] === '[' && hostname.at(-1) === ']')\n    hostname = hostname.slice(1, -1);                                                                                                                                         \n  hostname = hostname.replace(/\\.+$/, '').toLowerCase();\n                                                                                                                                                                              \n  let m;                                                                                                                                                                    \n  if ((m = hostname.match(ipv4MappedDotted))) return m[1];                                                                                                                    \n  if ((m = hostname.match(ipv4MappedHex)))    return hexToIPv4(m[1], m[2]);                                                                                                   \n  return hostname;                                                                                                                                                            \n};\n\n```\n\n### Impact\nAny application that sets NO_PROXY to exclude internal or metadata endpoints and uses an HTTP/HTTPS proxy can have those exclusions bypassed by a URL using IPv4-mapped IPv6 notation. The attacker must control the request URL. In cloud environments with instance metadata services, this can lead to credential exfiltration.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "axios"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.15.0"
      }, {
        "fixed" : "1.16.0"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "axios"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.32.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.31.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/axios/axios/security/advisories/GHSA-pjwm-pj3p-43mv"
  }, {
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  }, {
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  }, {
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  }, {
    "type" : "WEB",
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  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2487938"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/axios/axios"
  }, {
    "type" : "WEB",
    "url" : "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44492.json"
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  "database_specific" : {
    "cwe_ids" : [ "CWE-289", "CWE-918" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-29T15:59:30Z",
    "nvd_published_at" : "2026-06-11T17:16:33Z"
  }
}