CVE-2026-35146: HCL DFXServer Information Disclosure Flaw

CVE-2026-35146 Overview

CVE-2026-35146 is an unencrypted communication vulnerability affecting HCL DFXServer. The application permits users to establish connections over unencrypted HTTP channels rather than enforcing TLS. A remote attacker positioned on the network path can intercept traffic and read sensitive data transmitted between clients and the server. The weakness is classified under [CWE-326] Inadequate Encryption Strength. Exploitation requires user interaction, such as a user initiating an HTTP session, and does not require authentication.

Critical Impact
Attackers who observe network traffic between users and HCL DFXServer can capture credentials, session tokens, and application data exchanged in cleartext.

Affected Products

HCL DFXServer

Discovery Timeline

2026-07-16 - CVE-2026-35146 published to the National Vulnerability Database
2026-07-16 - Last updated in NVD database

Technical Details for CVE-2026-35146

Vulnerability Analysis

HCL DFXServer accepts client connections over plaintext HTTP. The server does not require Transport Layer Security (TLS) or redirect HTTP requests to HTTPS. All data transmitted during an unencrypted session—including authentication material, application commands, and response payloads—traverses the network in cleartext.

The issue maps to [CWE-326] Inadequate Encryption Strength. The application fails to enforce a cryptographic transport layer sufficient to protect confidentiality and integrity in transit. Because DFXServer is network-reachable and the affected connection is initiated by users, an attacker with visibility into the network path can passively collect data or actively modify it.

Root Cause

The root cause is the absence of enforced encrypted transport. The server permits HTTP as a valid connection method rather than restricting listeners to HTTPS. No configuration option or protocol negotiation forces clients to upgrade to a secure channel before sensitive data is exchanged.

Attack Vector

An attacker on the same network segment, in an upstream router, or in any intermediate position between client and server can perform passive interception or an active man-in-the-middle (MITM) attack. Techniques include ARP spoofing on a local network, DNS redirection, or interception on untrusted Wi-Fi. Once positioned, the attacker reads or modifies HTTP requests and responses in real time.

No verified proof-of-concept code has been published. Refer to the HCL Software Knowledge Base Article for vendor-provided technical detail.

Detection Methods for CVE-2026-35146

Indicators of Compromise

Inbound or outbound TCP connections to HCL DFXServer on port 80 or other non-TLS listeners.
HTTP request or response logs on DFXServer containing authentication headers, session cookies, or application data.
Unexpected ARP table changes or gratuitous ARP replies on network segments carrying DFXServer traffic.

Detection Strategies

Inspect DFXServer access logs for any request scheme of http:// rather than https://.
Use network sensors to flag cleartext HTTP sessions to DFXServer hosts and alert on credential-bearing headers.
Correlate client user-agent strings and source IPs against expected administrative networks to identify anomalous plaintext access.

Monitoring Recommendations

Enable full packet capture on network segments hosting DFXServer to support retrospective analysis of suspected interception.
Monitor TLS handshake failure rates and downgrade attempts on DFXServer endpoints.
Alert on new listeners bound to port 80 or other non-TLS ports on DFXServer systems.

How to Mitigate CVE-2026-35146

Immediate Actions Required

Disable HTTP listeners on HCL DFXServer and require HTTPS for all client connections.
Rotate any credentials, API keys, or session tokens that may have traversed HTTP sessions.
Restrict network access to DFXServer to trusted management networks until encrypted transport is enforced.

Patch Information

Consult the HCL Software Knowledge Base Article for vendor-supplied remediation guidance and configuration changes required to enforce encrypted communication.

Workarounds

Terminate DFXServer traffic behind a reverse proxy configured to accept only TLS 1.2 or TLS 1.3 and redirect HTTP to HTTPS.
Enforce HTTP Strict Transport Security (HSTS) at the proxy so browsers refuse to fall back to HTTP.
Segment DFXServer onto a dedicated VLAN and require VPN access to reduce exposure to on-path attackers.

bash

# Example nginx reverse proxy fronting DFXServer with TLS enforcement
server {
    listen 80;
    server_name dfxserver.example.com;
    return 301 https://$host$request_uri;
}

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

    ssl_certificate     /etc/ssl/certs/dfxserver.crt;
    ssl_certificate_key /etc/ssl/private/dfxserver.key;
    ssl_protocols       TLSv1.2 TLSv1.3;
    ssl_ciphers         HIGH:!aNULL:!MD5;

    add_header Strict-Transport-Security "max-age=63072000; includeSubDomains" always;

    location / {
        proxy_pass http://127.0.0.1:8080;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-Proto https;
    }
}