CVE-2026-18444

Executive Summary

CVE-2026-18444 is an integer conversion vulnerability (CWE-195) in NI LabVIEW that results in an out-of-bounds read when loading specially crafted VI (Virtual Instrument) files. The flaw affects NI LabVIEW 2026 Q3 and all prior versions, and exploitation requires user interaction—an attacker must convince a target to open a malicious VI file. Successful exploitation can lead to information disclosure or arbitrary code execution, with a CVSS base score of 6.6 (Medium), reflecting local attack vector, low complexity, and high availability impact.

Technical Analysis

The vulnerability resides in the image-loading subsystem of NI LabVIEW. According to the NVD description, an "integer conversion vulnerability" occurs during the loading of images within VI files, leading to an out-of-bounds read. CWE-195 is formally defined as "Signed to Unsigned Conversion Error," meaning a signed integer value is incorrectly converted to an unsigned integer, producing an unexpected large value that is then used as an index, size, or offset without proper bounds validation. In the context of image loading, this likely manifests when a crafted VI file specifies dimensions, offsets, or lengths that are parsed as signed and later treated as unsigned—causing the application to read beyond the allocated buffer.

The attack surface is the VI file format parser. NI LabVIEW VI files are compound binary files that can embed images (e.g., front panel graphics, icons, or documentation images). When LabVIEW opens a VI file, it reads these embedded image structures. A malformed integer field in the image metadata can trigger the out-of-bounds read. The CVSS vector (AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H) indicates that the attack is local (the file must be opened on the victim's machine), requires no privileges, and requires user interaction. The confidentiality and integrity impacts are low, but availability impact is high—suggesting that while data leakage or limited code execution is possible, a crash or denial of service is more likely.

No public exploit code or Nuclei template is available, though the PoC status is listed as "Public." This may indicate that a proof-of-concept exists in a researcher repository or advisory but has not been weaponized. The EPSS score is very low (0.00130, 2.2nd percentile), suggesting limited observed exploitation activity. CISA KEV does not list this CVE, and no threat actor campaigns are known.

The underlying issue is a classic memory-safety flaw. Out-of-bounds reads can leak memory contents (including pointers, credentials, or other sensitive data) or, if the read value is later used in a write or control-flow decision, can lead to arbitrary code execution. The high availability impact implies that a malformed file will likely crash LabVIEW, which is consistent with an out-of-bounds read that accesses unmapped memory.

Exploitation Scenarios

Based strictly on the NVD description and vulnerability class, the attack chain is as follows:

1. Reconnaissance / Target Identification: The attacker identifies individuals or organizations that use NI LabVIEW, such as engineering firms, research laboratories, and industrial control system (ICS) environments. LabVIEW is widely used in test, measurement, and control applications. The attacker may gather email addresses or file-sharing channels to deliver the malicious VI file.

2. Triggering the Flaw: The attacker crafts a VI file containing an embedded image with a manipulated integer field—for example, a negative value that is later interpreted as a large unsigned number during image loading. When the victim opens this VI file in NI LabVIEW 2026 Q3 or earlier, the parser performs an out-of-bounds read. The specific field and structure are not detailed in the NVD description, so the exact trigger cannot be confirmed without further technical analysis.

3. Payload / Execution Method: The out-of-bounds read can be used in two ways. First, it may disclose memory contents, which could include sensitive information such as credentials, cryptographic keys, or internal pointers. Second, if the read value influences subsequent memory operations or control flow, the attacker could achieve arbitrary code execution. However, the CVSS vector indicates only low confidentiality and integrity impact, suggesting that code execution may be difficult or unreliable, and the primary outcome is likely a crash (high availability impact).

4. Post-Exploitation Impact: If information disclosure is achieved, the attacker gains access to memory contents that could aid further attacks. If code execution is achieved, the attacker could run arbitrary code with the privileges of the user who opened the file. In both cases, a denial-of-service condition is highly likely due to the out-of-bounds read causing an access violation. No public PoC is available; the attack chain is inferred from the vulnerability class and CVSS vector.

Impact Assessment

The CVSS base score is 6.6 (Medium), with the vector CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H. This breaks down as follows:

• Attack Vector (Local): The attacker must deliver a file to the victim's system and have the victim open it. This limits the scale of exploitation compared to network-based attacks.
• Attack Complexity (Low): No special conditions are required beyond user interaction; the attacker can craft the file and rely on the victim to open it.
• Privileges Required (None): The attacker does not need prior access to the target system.
• User Interaction (Required): The victim must open the malicious VI file—this is the primary barrier.
• Scope (Unchanged): The vulnerability does not allow the attacker to affect resources beyond the security scope of the vulnerable component.
• Confidentiality (Low): Limited information disclosure possible.
• Integrity (Low): Limited ability to modify data or execute code.
• Availability (High): The vulnerability can cause a crash or denial of service, making LabVIEW unavailable.

Business impact includes potential downtime for engineering workstations, loss of unsaved work, and, in ICS environments, disruption of test and measurement processes. The blast radius is limited to systems where a user opens the malicious file. Given the low EPSS and no KEV listing, widespread exploitation is unlikely, but targeted attacks against high-value engineering or research targets are plausible.

Detection Guidance

Sigma Rule

title: Suspicious NI LabVIEW VI File Loading with Potential Out-of-Bounds Read
id: 8f4c2e1a-3b5d-4c7e-9f1a-2d6e8b0c4a7f
status: experimental
description: Detects loading of NI LabVIEW VI files that may trigger CVE-2026-18444 via crafted images
author: Threat Intelligence Team
date: 2026-01-01
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    Image|endswith: '\LabVIEW.exe'
    CommandLine|contains: '.vi'
  condition: selection
falsepositives:
  - Legitimate LabVIEW usage opening normal VI files
level: medium
tags:
  - attack.t1204
  - cve.2026.18444

YARA Rule

rule CVE_2026_18444_LabVIEW_VI_OOB
{
    meta:
        description = "Detects crafted NI LabVIEW VI files with potential malicious image structures for CVE-2026-18444"
        author = "Threat Intelligence Team"
        date = "2026-01-01"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-18444"
        hash = "unknown"
    strings:
        $vi_magic = { 4C 56 49 46 } // "LVIF" - LabVIEW VI file signature (example; actual signature may differ)
        $img_marker = "IMG" nocase
        $png_magic = { 89 50 4E 47 0D 0A 1A 0A }
        $jpg_magic = { FF D8 FF }
    condition:
        $vi_magic at 0 and any of ($img_marker, $png_magic, $jpg_magic)
}

Note: The VI file signature and image markers are illustrative; exact byte patterns must be validated against real LabVIEW VI files.

Suricata IDS Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2026-18444 NI LabVIEW VI File Transfer with Embedded Image"; flow:to_server,established; fileext:"vi"; filemagic:"LabVIEW"; classtype:attempted-user; sid:1000001; rev:1;)

This rule triggers on outbound transfer of a VI file; since the attack is local, network detection is limited to file delivery via email or file share.

Elastic Detection

process where process.name == "LabVIEW.exe" and process.args : "*.vi"

This EQL rule detects the execution of LabVIEW with a VI file argument, which is a prerequisite for exploitation. Correlate with subsequent crash events or unusual memory access.

Splunk SPL Query

index=windows EventCode=1 Image="*\\LabVIEW.exe" CommandLine="*.vi"
| stats count by User, CommandLine, ComputerName
| where count > 0

This query identifies LabVIEW processes launched with VI files. For better fidelity, join with application crash logs (EventCode 1000) for LabVIEW.exe.

Wazuh OSSEC Rule

<group name="labview,cve-2026-18444,">
  <rule id="100001" level="10">
    <if_sid>60000</if_sid>
    <field name="win.eventdata.image">LabVIEW.exe</field>
    <field name="win.eventdata.commandLine">\.vi</field>
    <description>CVE-2026-18444: NI LabVIEW opened a VI file - possible exploitation attempt</description>
    <mitre>
      <id>T1204</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence is 2/4 (CLAIMED — single source claims patch, not independently confirmed). NVD indicates a patch, but no vendor advisory or version reference is available.

1. Immediate Mitigations:

   • Do not open VI files from untrusted sources. Implement email and web gateway filtering to block VI file attachments.
   • Use application allowlisting to restrict execution of LabVIEW to authorized users and paths.
   • Enable exploit protection features (e.g., Windows Defender Exploit Guard) for LabVIEW.exe to mitigate out-of-bounds read exploitation.
   • Monitor for crashes of LabVIEW.exe (Event ID 1000) as a potential indicator of exploitation attempts.

2. Patch/Upgrade Steps:

   • Monitor NI's official security advisory page for CVE-2026-18444 to obtain the patched version. Since NVD claims a patch, it may be available as a LabVIEW update or service pack. Apply the latest LabVIEW version once released.
   • If no patch is available, consider isolating LabVIEW workstations from critical networks and limiting file-sharing capabilities.

3. Long-Term Hardening:

   • Implement a vulnerability management program that tracks NI security advisories.
   • Sandbox or containerize LabVIEW when processing untrusted VI files.
   • Conduct user awareness training on the risks of opening unsolicited files, especially from unknown sources.
   • Adopt memory-safe configurations and enable Control Flow Guard (CFG) and Data Execution Prevention (DEP) for LabVIEW.

References

1. NVD - CVE-2026-18444: https://nvd.nist.gov/vuln/detail/CVE-2026-18444
2. NI Security Advisory (placeholder; check NI website for updates): https://www.ni.com/en-us/support/documentation/security.html
3. CWE-195: Signed to Unsigned Conversion Error: https://cwe.mitre.org/data/definitions/195.html
4. MITRE ATT&CK T1204: User Execution: https://attack.mitre.org/techniques/T1204/
5. CISA KEV Catalog (CVE-2026-18444 not listed as of report date): https://www.cisa.gov/known-exploited-vulnerabilities-catalog

No known threat actor campaigns or exploit-in-the-wild evidence are available for this CVE. The EPSS score is 0.00130, indicating a very low probability of exploitation in the wild.