Siemens SIMATIC S7-1500 CPU 1518 MFP NULL Pointer Dereference (CVE-2026-40355)

high Tenable OT Security Plugin ID 505649

Synopsis

The remote OT asset is affected by a vulnerability.

Description

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.

Solution

Refer to the vendor advisory.

Plugin Details

Severity: High

ID: 505649

File Name: tenable_ot_siemens_CVE-2026-40355.nasl

Version: 1.3

Type: Remote

Family: Tenable.ot

Published: 7/27/2026

Updated: 7/30/2026

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.75

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.1

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

CVSS Score Source: CVE-2026-40355

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.7

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:siemens:simatic_s7-1500_cpu_firmware:3.1.5, cpe:/o:siemens:simatic_s7-1500_cpu_firmware:3.1.6, cpe:/o:siemens:siplus_s7-1500_cpu_firmware, cpe:/o:siemens:siplus_s7-1500_cpu_firmware:3.1.6

Required KB Items: Tenable.ot/Siemens

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 6/10/2025

Vulnerability Publication Date: 4/28/2026

Reference Information

CVE: CVE-2026-40355

CWE: 476

ICSA: 26-209-04

Detections

Analytics