LOYTEC L-IP BACnet/IP Routers Out-of-bounds Read (CVE-2026-55732)

high Tenable OT Security Plugin ID 505945

Synopsis

The remote OT asset is affected by a vulnerability.

Description

The BACnet packet parser of a LOYTEC L-IP BACnet/IP router reads out of bounds of the internal 'bacdt_days_till_month' lookup table in 'bacdt_datetime_to_tod()' when it processes a malformed BACnet TimeSynchronization or UTC-TimeSynchronization packet carrying an invalid month value. An unauthenticated remote attacker can send such a packet to crash the device's 'linx_a64.exe' process; because this process provides core services beyond BACnet, repeated crashes cause the device to fully reboot.

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

Solution

Upgrade to firmware version 8.4.20 or later.

Plugin Details

Severity: High

ID: 505945

File Name: tenable_ot_loytecelectronics_CVE-2026-55732.nasl

Version: 1.3

Type: Remote

Family: Tenable.ot

Published: 9/7/2026

Updated: 10/8/2026

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.75

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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:U/RL:O/RC:C

CVSS v4

Risk Factor: High

Base Score: 8.7

Threat Score: 6.6

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Vulnerability Information

CPE: cpe:/o:loytec:lip-me201c_firmware, cpe:/o:loytec:lip-me202c_firmware, cpe:/o:loytec:lip-me204c_firmware

Required KB Items: Tenable.ot/LOYTECElectronics

Exploit Ease: No known exploits are available

Patch Publication Date: 7/3/2026

Vulnerability Publication Date: 7/3/2026

Reference Information

CVE: CVE-2026-55732

CWE: 125

Detections

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