CVE-2026-41036: Quantum Networks Router RCE Vulnerability

CVE-2026-41036 Overview

This vulnerability exists in Quantum Networks router due to inadequate sanitization of user-supplied input in the management CLI interface. An authenticated remote attacker could exploit this vulnerability by injecting arbitrary OS commands on the targeted device.

Successful exploitation of this vulnerability could allow the attacker to perform remote code execution with root privileges on the targeted device.

Critical Impact

Authenticated attackers can achieve root-level remote code execution on affected Quantum Networks routers through command injection in the management CLI interface.

Affected Products

• Quantum Networks Router (Management CLI Interface)

Discovery Timeline

• April 21, 2026 - CVE CVE-2026-41036 published to NVD
• April 21, 2026 - Last updated in NVD database

Technical Details for CVE-2026-41036

Vulnerability Analysis

This command injection vulnerability (CWE-78: Improper Neutralization of Special Elements used in an OS Command) affects the management CLI interface of Quantum Networks routers. The vulnerability stems from the application's failure to properly sanitize user-supplied input before incorporating it into operating system commands.

When an authenticated user interacts with the management CLI, certain input fields accept user-controlled data that is subsequently passed to underlying OS command execution functions. The lack of proper input validation and sanitization allows attackers to inject shell metacharacters and arbitrary commands that execute with the privileges of the router's operating system—in this case, root privileges.

The network-accessible nature of this vulnerability combined with the low attack complexity makes it particularly concerning for organizations relying on these routers for network infrastructure. While authentication is required, once an attacker has valid credentials, exploitation is straightforward and provides complete control over the affected device.

Root Cause

The root cause of this vulnerability is improper input validation in the management CLI interface. The application fails to adequately sanitize special characters and shell metacharacters from user-supplied input before passing it to system command execution functions. This allows command separator characters (such as ;, |, &&, or backticks) to break out of the intended command context and execute arbitrary commands.

Attack Vector

The attack vector is network-based, requiring an authenticated remote attacker to access the management CLI interface. The attacker leverages valid credentials to authenticate to the router's management interface, then crafts malicious input containing OS command injection payloads. When the vulnerable CLI command processes this input, the injected commands execute with root privileges on the underlying operating system.

Typical exploitation involves:

1. Authenticating to the router's management CLI interface
2. Identifying input fields that are processed by system commands
3. Injecting shell metacharacters followed by arbitrary commands
4. Achieving command execution with root privileges

The vulnerability does not require user interaction beyond the initial authentication, and the attacker can leverage the elevated privileges to install backdoors, exfiltrate configuration data, pivot to other network segments, or disrupt network operations.

Detection Methods for CVE-2026-41036

Indicators of Compromise

• Unusual command patterns in CLI session logs containing shell metacharacters (;, |, &&, ||, backticks)
• Unexpected processes spawned from router management services
• Unauthorized configuration changes or new user accounts on router devices
• Outbound network connections from router to unknown external hosts

Detection Strategies

• Monitor authentication logs for suspicious login attempts or unusual access patterns to the management CLI
• Implement network-based intrusion detection rules to identify command injection payloads in CLI traffic
• Review router logs for commands containing common injection patterns or unexpected system command executions
• Deploy behavioral analysis to detect anomalous process creation or network activity from router devices

Monitoring Recommendations

• Enable comprehensive logging on all management interfaces and forward logs to a centralized SIEM
• Configure alerts for authentication events from unexpected source IPs or during unusual hours
• Implement session monitoring for CLI management interfaces to capture command history
• Establish baseline behavior for router processes and alert on deviations

How to Mitigate CVE-2026-41036

Immediate Actions Required

• Restrict access to the management CLI interface to trusted IP addresses using access control lists (ACLs)
• Implement strong authentication mechanisms including multi-factor authentication where supported
• Segment management interfaces on isolated network segments not accessible from general user networks
• Review and audit all accounts with CLI access privileges and remove unnecessary accounts

Patch Information

Refer to the vendor advisory and CERT-In Vulnerability Note CIVN-2026-0200 for official patch information and firmware updates from Quantum Networks. Organizations should apply security patches as soon as they become available from the vendor.

Workarounds

• Disable remote CLI access and use only local console connections for management tasks until patches are applied
• Implement a jump host or bastion server for accessing router management interfaces with additional logging and access controls
• Deploy network access control policies to limit which users and systems can reach router management ports
• Enable command authorization and accounting features to log and restrict which commands authenticated users can execute

# Configuration example - Restrict management access to specific IP range
# Example ACL configuration (syntax varies by router model)
access-list management permit ip 10.0.100.0/24 any
interface management
  ip access-group management in