Siemens SIMATIC S7-1500 TM MFP Improper Input Validation (CVE-2026-53255)

high Tenable OT Security Plugin ID 506277

Synopsis

The remote OT asset is affected by a vulnerability.

Description

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

Bluetooth: MGMT: validate advertising TLV before type checks

tlv_data_is_valid() reads each advertising data field length from data[i], then inspects data[i + 1] for managed EIR types before checking that the current field still fits inside the supplied buffer.

A malformed field whose length byte is the last byte of the buffer can therefore make the parser read one byte past the advertising data.

KASAN reported the following when a malformed MGMT_OP_ADD_ADVERTISING request reached that path:

BUG: KASAN: vmalloc-out-of-bounds in tlv_data_is_valid() Read of size 1 Call trace:
tlv_data_is_valid() add_advertising() hci_mgmt_cmd() hci_sock_sendmsg()

Move the existing element-length check before any type-octet inspection so each non-empty element is proven to contain its type byte before the parser looks at data[i + 1].

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: 506277

File Name: tenable_ot_siemens_CVE-2026-53255.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: Medium

Score: 4.3

Percentile: 53.64

CVSS v3

Risk Factor: High

Base Score: 7.1

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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-2026-53255

CWE: 20

Detections

Analytics