CVE-2026-23718: Siemens Simcenter Femap RCE Vulnerability

CVE-2026-23718 Overview

A critical out-of-bounds read vulnerability has been identified in Siemens Simcenter Femap and Simcenter Nastran, affecting all versions prior to V2512. The affected applications contain an out-of-bounds read vulnerability while parsing specially crafted NDB files. This vulnerability could allow an attacker to execute arbitrary code in the context of the current process, potentially leading to full system compromise.

Critical Impact

Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code with the privileges of the current user, potentially leading to data theft, system compromise, or further lateral movement within the network.

Affected Products

• Siemens Simcenter Femap (All versions < V2512)
• Siemens Simcenter Nastran (All versions < V2512)

Discovery Timeline

• 2026-02-10 - CVE-2026-23718 published to NVD
• 2026-02-11 - Last updated in NVD database

Technical Details for CVE-2026-23718

Vulnerability Analysis

This vulnerability (CWE-125: Out-of-Bounds Read) occurs during the parsing of NDB files within Simcenter Femap and Simcenter Nastran applications. When a specially crafted NDB file is processed, the application fails to properly validate memory boundaries, allowing read operations beyond the allocated buffer. This memory corruption can be leveraged by attackers to achieve code execution within the context of the running process.

The local attack vector requires user interaction, meaning an attacker must convince a victim to open a malicious NDB file. This is typically accomplished through social engineering tactics such as phishing emails or hosting malicious files on compromised websites frequented by engineering professionals who use these simulation tools.

Root Cause

The root cause of this vulnerability lies in insufficient bounds checking within the NDB file parsing functionality. When processing NDB file structures, the application reads data without properly validating that the read operation stays within the boundaries of allocated memory. This allows attackers to craft malicious NDB files that trigger out-of-bounds memory access, potentially disclosing sensitive memory contents or corrupting memory in ways that enable code execution.

Attack Vector

The attack requires local access and user interaction. An attacker must craft a malicious NDB file and convince a user to open it using either Simcenter Femap or Simcenter Nastran. The attack flow typically involves:

1. The attacker creates a specially crafted NDB file with malformed data structures designed to trigger the out-of-bounds read
2. The attacker delivers the malicious file to the target via email, file sharing, or other distribution methods
3. The victim opens the malicious NDB file using the vulnerable application
4. During parsing, the application reads beyond allocated buffer boundaries
5. The attacker leverages this memory corruption to execute arbitrary code with the privileges of the current user

Due to the technical nature of Simcenter Femap and Nastran as engineering simulation software, targets are likely to be engineers and technical professionals in industries such as aerospace, automotive, and manufacturing—making this vulnerability particularly relevant for industrial espionage scenarios.

Detection Methods for CVE-2026-23718

Indicators of Compromise

• Unexpected crashes or hangs in Simcenter Femap or Simcenter Nastran when opening NDB files
• Unusual process behavior following NDB file operations, such as unexpected network connections or child process creation
• Memory access violations or application error logs indicating buffer overruns during file parsing
• Suspicious NDB files received via email or downloaded from untrusted sources

Detection Strategies

• Deploy endpoint detection and response (EDR) solutions to monitor for suspicious process behavior following NDB file operations
• Implement file integrity monitoring for directories containing NDB files used in engineering workflows
• Configure application whitelisting to prevent unauthorized executables from launching from user-writable directories
• Enable Windows Event Logging for application crashes and monitor for patterns involving Simcenter applications

Monitoring Recommendations

• Monitor for unusual file access patterns involving .ndb file extensions from unexpected sources
• Implement network monitoring to detect potential data exfiltration following successful exploitation
• Set up alerts for application crashes or memory violations in Simcenter Femap and Nastran processes
• Review email gateway logs for incoming NDB file attachments from external sources

How to Mitigate CVE-2026-23718

Immediate Actions Required

• Update Simcenter Femap and Simcenter Nastran to version V2512 or later immediately
• Implement strict policies regarding the handling of NDB files from untrusted sources
• Educate users about the risks of opening engineering files from unknown or untrusted origins
• Consider temporarily restricting NDB file handling to isolated or sandboxed environments until patching is complete

Patch Information

Siemens has released security updates addressing this vulnerability. Organizations should upgrade affected installations to Simcenter Femap V2512 or later and Simcenter Nastran V2512 or later. Detailed patch information is available in the Siemens Security Advisory SSA-965753.

Workarounds

• Avoid opening NDB files from untrusted or unknown sources until systems are patched
• Implement network segmentation to limit potential impact if exploitation occurs
• Run Simcenter applications with minimal privileges using the principle of least privilege
• Consider using application sandboxing solutions to contain potential exploitation attempts

# Configuration example - Restrict NDB file handling on Windows systems
# Add Group Policy restriction for NDB file associations
# Run in elevated PowerShell

# Create backup of current file association
reg export "HKEY_CLASSES_ROOT\.ndb" "C:\backup\ndb_association_backup.reg"

# Disable direct execution of NDB files from email attachments
# Configure Outlook to block NDB attachments
Set-ItemProperty -Path "HKCU:\Software\Microsoft\Office\16.0\Outlook\Security" -Name "Level1Remove" -Value ""