CVE-2026-3094: Delta CNCSoft-G2 RCE Vulnerability

CVE-2026-3094 Overview

Delta Electronics CNCSoft-G2 contains an out-of-bounds write vulnerability due to improper validation of user-supplied files. When a user opens a specially crafted malicious file, an attacker can exploit this flaw to execute arbitrary code in the context of the current process. This vulnerability affects industrial automation software used in CNC machine control environments, making it particularly concerning for manufacturing and industrial control system (ICS) environments.

Critical Impact

Successful exploitation allows attackers to execute arbitrary code with the privileges of the current user, potentially leading to full system compromise in industrial control environments.

Affected Products

• Delta Electronics CNCSoft-G2

Discovery Timeline

• March 4, 2026 - CVE-2026-3094 published to NVD
• March 4, 2026 - Last updated in NVD database

Technical Details for CVE-2026-3094

Vulnerability Analysis

This vulnerability is classified as CWE-787 (Out-of-Bounds Write), which occurs when the CNCSoft-G2 application writes data past the end or before the beginning of an intended buffer during file parsing operations. The lack of proper validation of user-supplied files allows malformed input to trigger memory corruption, enabling an attacker to overwrite adjacent memory locations with attacker-controlled data.

The attack requires local access and user interaction—specifically, a victim must open a malicious file crafted by the attacker. Once opened, the file parsing routines fail to properly validate input boundaries, leading to the out-of-bounds write condition. This can corrupt critical data structures, function pointers, or return addresses, ultimately allowing the attacker to hijack program execution flow.

Root Cause

The root cause of this vulnerability lies in insufficient input validation within the file parsing functionality of CNCSoft-G2. The application fails to properly verify the size and structure of user-supplied data before writing it to memory buffers. When processing maliciously crafted files, the application does not enforce adequate boundary checks, allowing write operations to exceed allocated buffer sizes.

Attack Vector

The attack vector requires local access where an attacker must convince a user to open a malicious file. This is typically accomplished through social engineering tactics such as phishing emails with malicious attachments, compromised file shares in industrial environments, or supply chain attacks targeting project files shared between engineering teams. Once the victim opens the crafted file in CNCSoft-G2, the vulnerability is triggered during the file parsing process, and the attacker's code executes with the same privileges as the application.

The vulnerability mechanism involves improper boundary validation during file parsing operations in CNCSoft-G2. When the application processes project files, it reads structured data and writes values to memory buffers. Without proper size validation, an attacker can craft a file containing oversized or malformed data fields that cause write operations to exceed buffer boundaries. For technical details, refer to the Delta Security Advisory.

Detection Methods for CVE-2026-3094

Indicators of Compromise

• Unexpected crashes or abnormal termination of the CNCSoft-G2 application
• Presence of suspicious or unfamiliar project files in CNCSoft-G2 working directories
• Unusual process spawning from the CNCSoft-G2 process
• Memory access violations or exception logs related to CNCSoft-G2

Detection Strategies

• Monitor for anomalous file access patterns targeting CNCSoft-G2 project files
• Implement endpoint detection rules for memory corruption exploitation techniques
• Deploy application whitelisting to prevent unauthorized code execution from CNCSoft-G2 context
• Enable detailed logging of file operations on engineering workstations running CNCSoft-G2

Monitoring Recommendations

• Establish baseline behavior for CNCSoft-G2 processes and alert on deviations
• Monitor network shares and file repositories for suspicious project files
• Implement file integrity monitoring on CNCSoft-G2 installation directories
• Review email security logs for attachments matching CNCSoft-G2 project file extensions

How to Mitigate CVE-2026-3094

Immediate Actions Required

• Do not open CNCSoft-G2 project files from untrusted or unknown sources
• Isolate engineering workstations running CNCSoft-G2 from general network access
• Review and validate all project files before opening, especially those received via email or external media
• Apply the latest security updates from Delta Electronics when available

Patch Information

Delta Electronics has released a security advisory addressing this vulnerability. Organizations should consult the Delta Security Advisory for specific patch information and update instructions. It is recommended to update CNCSoft-G2 to the latest available version that addresses this file parsing vulnerability.

Workarounds

• Restrict file access permissions for CNCSoft-G2 project files to authorized users only
• Implement strict email filtering policies to quarantine potentially malicious attachments
• Deploy application sandboxing for CNCSoft-G2 to limit the impact of exploitation
• Maintain offline backups of critical project files and system configurations

# Network isolation example for ICS workstations
# Restrict CNCSoft-G2 workstation to communicate only with necessary CNC equipment
iptables -A OUTPUT -p tcp -d 192.168.100.0/24 -j ACCEPT
iptables -A OUTPUT -p tcp -j DROP