CVE-2026-41039: Quantum Networks Router Info Disclosure

CVE-2026-41039 Overview

This vulnerability exists in Quantum Networks router due to improper access control and insecure default configuration in the web-based management interface. An unauthenticated attacker could exploit this vulnerability by accessing exposed API endpoints on the targeted device.

Successful exploitation of this vulnerability could allow the attacker to access sensitive information, including internal endpoints, scripts and directories on the targeted device.

Critical Impact

Unauthenticated attackers can access sensitive information on Quantum Networks routers through exposed API endpoints due to missing authentication controls.

Affected Products

• Quantum Networks Router (web-based management interface)

Discovery Timeline

• April 21, 2026 - CVE-2026-41039 published to NVD
• April 21, 2026 - Last updated in NVD database

Technical Details for CVE-2026-41039

Vulnerability Analysis

This vulnerability stems from Missing Authentication for Critical Function (CWE-306) in the Quantum Networks router web-based management interface. The affected router exposes API endpoints without implementing proper authentication controls, allowing unauthenticated remote attackers to access functionality that should be restricted to authorized administrators only.

The network-accessible attack surface combined with low attack complexity makes this vulnerability particularly concerning for organizations with internet-exposed Quantum Networks routers. No user interaction is required for exploitation, meaning automated scanning and exploitation tools can identify and attack vulnerable devices at scale.

Root Cause

The root cause is improper access control implementation combined with insecure default configuration in the router's web-based management interface. The API endpoints lack authentication requirements, violating the principle of defense in depth. This represents a CWE-306 (Missing Authentication for Critical Function) weakness where security-critical functionality is accessible without verifying the identity of the requesting party.

Attack Vector

The attack vector is network-based, requiring the attacker to have network access to the router's web management interface. An unauthenticated attacker can directly access exposed API endpoints on the targeted device without providing any credentials. The attack flow involves:

1. Attacker identifies a Quantum Networks router with an exposed web management interface
2. Attacker enumerates or discovers unprotected API endpoints
3. Attacker sends requests to these endpoints without authentication
4. The router responds with sensitive information including internal endpoints, scripts, and directory structures

For technical details, refer to the CERT-IN Vulnerability Note CIVN-2026-0200.

Detection Methods for CVE-2026-41039

Indicators of Compromise

• Unusual or unexpected HTTP/HTTPS requests to the router's web management interface from external IP addresses
• Multiple unauthenticated API endpoint access attempts in router access logs
• Evidence of directory enumeration or API endpoint scanning activity
• Unexpected data exfiltration from the router management interface

Detection Strategies

• Monitor network traffic for unauthenticated requests to the router's web management API endpoints
• Implement web application firewall (WAF) rules to detect and block suspicious API enumeration patterns
• Deploy intrusion detection signatures for known exploitation attempts targeting Quantum Networks routers
• Review router access logs for anomalous patterns of requests to sensitive endpoints

Monitoring Recommendations

• Enable comprehensive logging on Quantum Networks router web management interfaces
• Configure SIEM alerts for unusual access patterns to router management interfaces
• Monitor for reconnaissance activities targeting network infrastructure devices
• Implement network segmentation monitoring to detect lateral movement attempts following information disclosure

How to Mitigate CVE-2026-41039

Immediate Actions Required

• Restrict access to the web-based management interface to trusted internal networks only
• Implement firewall rules to block external access to router management ports
• Enable authentication on all API endpoints if configuration options are available
• Review and audit current router configurations for insecure default settings

Patch Information

Consult the CERT-IN Vulnerability Note CIVN-2026-0200 for official patch information and vendor guidance. Contact Quantum Networks support for the latest firmware updates that address this vulnerability.

Workarounds

• Place router management interfaces behind a VPN or jump host requiring authentication
• Use network access control lists (ACLs) to restrict management interface access to authorized IP addresses
• Disable the web-based management interface if not required and use alternative management methods
• Implement network segmentation to isolate management traffic from general network traffic

# Example firewall rule to restrict management interface access
# Adjust interface and IP addresses as appropriate for your environment
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP