CVE-2026-46398: HAX CMS Information Disclosure Flaw

CVE-2026-46398 Overview

CVE-2026-46398 affects HAX CMS, an open-source content management system that manages microsite ecosystems using PHP or Node.js backends. The vulnerability stems from the haxcms_refresh_token cookie being issued without the Secure attribute. As a result, the cookie can traverse unencrypted HTTP connections, exposing it to network-based interception. The flaw is tracked under CWE-614: Sensitive Cookie in HTTPS Session Without 'Secure' Attribute and is present in versions 25.0.0 through 25.x. Version 26.0.0 remediates the issue.

Critical Impact

Attackers positioned on the network path can capture the haxcms_refresh_token cookie in cleartext and reuse it to hijack authenticated HAX CMS sessions.

Affected Products

• HAX CMS (PHP backend) versions 25.0.0 through 25.x
• HAX CMS (Node.js backend) versions 25.0.0 through 25.x
• Fixed in HAX CMS version 26.0.0

Discovery Timeline

• 2026-06-05 - CVE-2026-46398 published to NVD
• 2026-06-05 - Last updated in NVD database

Technical Details for CVE-2026-46398

Vulnerability Analysis

HAX CMS issues a persistent authentication artifact named haxcms_refresh_token to maintain user sessions across requests. In affected releases, the application sets this cookie without the Secure flag. The Secure attribute instructs browsers to transmit a cookie only over Transport Layer Security (TLS) connections. Without it, the browser attaches the cookie to any matching request, including plaintext HTTP traffic.

An attacker with passive access to the network path can read the cookie value during transit. Common positions include public Wi-Fi networks, compromised routers, and shared LAN segments. Once captured, the refresh token allows the attacker to mint new access tokens and impersonate the victim.

Root Cause

The root cause is missing cookie attribute hardening in the authentication flow. The Set-Cookie response header omits the Secure directive when issuing haxcms_refresh_token. This violates standard guidance for sensitive session cookies and falls under [CWE-614].

Attack Vector

Exploitation requires the attacker to observe network traffic between the victim browser and the HAX CMS server. The attack succeeds when any HTTP request matching the cookie scope is issued, including mixed-content scenarios, downgrade attempts, or misconfigured links. No user interaction beyond normal browsing is required. The captured refresh token then enables session hijacking against the HAX CMS application.

No verified proof-of-concept code is published. See the GitHub Security Advisory GHSA-g7v2-r32q-jf5v for vendor details.

Detection Methods for CVE-2026-46398

Indicators of Compromise

• Set-Cookie response headers from HAX CMS containing haxcms_refresh_token without the Secure attribute
• Authentication events for a single HAX CMS account originating from geographically or network-disparate source IP addresses
• Refresh token reuse from a client fingerprint that differs from the original issuing session

Detection Strategies

• Inspect HTTP responses from HAX CMS instances and flag any Set-Cookie: haxcms_refresh_token=... header missing the Secure and HttpOnly flags
• Correlate authentication logs to identify refresh token usage from multiple IP addresses or user agents within short time windows
• Run version inventory queries against HAX CMS deployments to identify hosts running versions prior to 26.0.0

Monitoring Recommendations

• Forward HAX CMS access and authentication logs to a centralized analytics platform for session anomaly detection
• Monitor for HTTP listeners on HAX CMS servers and alert on any plaintext bind that could expose cookies
• Track refresh token issuance and consumption rates to surface abnormal token replay patterns

How to Mitigate CVE-2026-46398

Immediate Actions Required

• Upgrade all HAX CMS instances to version 26.0.0 or later
• Force invalidation of existing haxcms_refresh_token values to revoke tokens potentially captured before the upgrade
• Require all HAX CMS traffic to use HTTPS and disable HTTP listeners at the web server or reverse proxy layer

Patch Information

The maintainers released HAX CMS version 26.0.0, which sets the Secure attribute on the haxcms_refresh_token cookie. Administrators should apply the upgrade as documented in the GitHub Security Advisory GHSA-g7v2-r32q-jf5v.

Workarounds

• Terminate TLS at a reverse proxy and configure it to rewrite outbound Set-Cookie headers to append the Secure flag
• Enforce HTTP Strict Transport Security (HSTS) with includeSubDomains to prevent browsers from issuing plaintext requests that would expose the cookie
• Restrict HAX CMS administrative access to trusted networks or VPN segments until the patch is applied

# Example nginx configuration to enforce HTTPS and harden cookies
server {
    listen 80;
    server_name haxcms.example.com;
    return 301 https://$host$request_uri;
}

server {
    listen 443 ssl http2;
    server_name haxcms.example.com;

    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
    proxy_cookie_flags haxcms_refresh_token secure httponly samesite=strict;

    location / {
        proxy_pass http://127.0.0.1:8080;
    }
}