Siemens SIMATIC S7-1500 TM MFP Improper Input Validation (CVE-2026-46026)

medium Tenable OT Security Plugin ID 506346

Synopsis

The remote OT asset is affected by a vulnerability.

Description

In the Linux kernel, the following vulnerability has been resolved:

net: qrtr: ns: Limit the maximum number of lookups

Current code does no bound checking on the number of lookups a client can perform. Though the code restricts the lookups to local clients, there is still a possibility of a malicious local client sending a flood of NEW_LOOKUP messages over the same socket.

Fix this issue by limiting the maximum number of lookups to 64 globally.
Since the nameserver allows only atmost one local observer, this global lookup count will ensure that the lookups stay within the limit.

Note that, limit of 64 is chosen based on the current platform requirements. If requirement changes in the future, this limit can be increased.

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: Medium

ID: 506346

File Name: tenable_ot_siemens_CVE-2026-46026.nasl

Version: 1.1

Type: Remote

Family: Tenable.ot

Published: 10/20/2026

Updated: 10/20/2026

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.63

CVSS v3

Risk Factor: Medium

Base Score: 5.5

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

Vulnerability Information

CPE: cpe:/o:siemens:simatic_s7-1500_tm_mfp

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 10/13/2026

Vulnerability Publication Date: 10/13/2026

Reference Information

CVE: CVE-2026-46026

CWE: 20

Detections

Analytics