CVE-2026-18445: NI LabVIEW Integer Overflow RCE Vulnerability

CVE-2026-18445 Overview

CVE-2026-18445 is an integer overflow vulnerability in NI LabVIEW that leads to an out-of-bounds write condition. The flaw affects NI LabVIEW 2026 Q3 and all prior versions. Successful exploitation requires a user to open a specially crafted Virtual Instrument (.VI) file. An attacker who convinces a user to open a malicious VI file can trigger information disclosure or arbitrary code execution in the context of the LabVIEW process. The weakness is classified under CWE-190: Integer Overflow or Wraparound.

Critical Impact
Attackers can achieve arbitrary code execution or leak process memory by delivering a crafted VI file to a LabVIEW user.

Affected Products

NI LabVIEW 2026 Q3
NI LabVIEW versions prior to 2026 Q3
Systems processing untrusted .VI files with vulnerable LabVIEW builds

Discovery Timeline

2026-08-25 - CVE-2026-18445 published to the National Vulnerability Database
2026-08-27 - Last updated in NVD database

Technical Details for CVE-2026-18445

Vulnerability Analysis

The vulnerability resides in the LabVIEW parser responsible for reading VI file structures. During parsing, an integer value derived from file-supplied data overflows arithmetic bounds. The resulting undersized allocation or miscalculated index enables a subsequent write past the intended memory buffer. Because the flaw allows attacker-controlled data to be written outside a validated region, it can corrupt adjacent objects, function pointers, or heap metadata. Exploitation results in either information disclosure or arbitrary code execution within the LabVIEW process. The attack vector is local and requires user interaction, since the victim must open the crafted VI file.

Root Cause

The root cause is unchecked arithmetic on size or length fields parsed from a .VI file [CWE-190]. When the computed value wraps around the integer type maximum, LabVIEW allocates or indexes a buffer that is smaller than the amount of data written. The parser does not validate the arithmetic result before using it as a bound, so oversized or maliciously crafted length fields drive the out-of-bounds write.

Attack Vector

An attacker crafts a malicious .VI file containing manipulated length or size fields designed to overflow LabVIEW's parsing arithmetic. The attacker delivers the file through phishing, shared engineering repositories, USB media, or code-collaboration platforms common in industrial and research environments. When a LabVIEW user opens the file, the parser triggers the out-of-bounds write. No network exposure is required; exploitation depends entirely on user interaction with the crafted file.

No public proof-of-concept or exploit code is available for CVE-2026-18445. For authoritative technical details, refer to the NI Security Update Advisory.

Detection Methods for CVE-2026-18445

Indicators of Compromise

Unexpected crashes or exceptions in LabVIEW.exe immediately after opening a .VI file from an untrusted source.
Creation of child processes (for example, cmd.exe, powershell.exe, or rundll32.exe) spawned by the LabVIEW process.
New or modified files in user-writable directories following the opening of a suspicious .VI attachment.
Outbound network connections initiated by LabVIEW.exe to unrecognized hosts.

Detection Strategies

Alert on process lineage where LabVIEW.exe spawns interpreters, shells, or living-off-the-land binaries.
Inspect email gateways and file-sharing services for .VI files originating outside the trusted engineering supply chain.
Correlate LabVIEW crash telemetry with recent file-open events to identify potential exploitation attempts.

Monitoring Recommendations

Enable EDR telemetry on engineering and lab workstations that run LabVIEW.
Log all .VI file executions and correlate with user identity and file origin.
Monitor for unusual memory access violations reported by Windows Error Reporting from LabVIEW.exe.

How to Mitigate CVE-2026-18445

Immediate Actions Required

Apply the fixed LabVIEW build published by NI as soon as it is available in your environment.
Instruct engineering and research staff not to open .VI files received from untrusted or unverified sources.
Inventory all LabVIEW installations to identify systems running 2026 Q3 or earlier.
Restrict administrative privileges on workstations that routinely process external .VI files.

Patch Information

NI has published guidance and update information in the NI Security Update Advisory. Administrators should upgrade LabVIEW to the fixed release identified in that advisory and validate the version on each engineering workstation.

Workarounds

Only open .VI files from verified, internally trusted sources or authenticated version control systems.
Use application allowlisting to restrict which users can launch LabVIEW and open externally sourced files.
Run LabVIEW under standard user accounts to limit impact of successful code execution.
Quarantine inbound .VI attachments at the mail gateway pending manual review.

bash

# Example: identify LabVIEW installations across Windows endpoints
reg query "HKLM\SOFTWARE\National Instruments\LabVIEW" /s /v Version

# Example: block execution of VI files from user download directories via AppLocker rule
New-AppLockerPolicy -RuleType Path -User Everyone `
  -Action Deny -Path "%USERPROFILE%\Downloads\*.vi"