Detections
Analytics

Hitachi Energy RTU500 NULL Pointer Dereference (CVE-2026-32778)

medium Tenable OT Security Plugin ID 505376

Synopsis

The remote OT asset is affected by a vulnerability.

Description

libexpat before 2.7.5 allows a NULL pointer dereference in the function setContext on retry after an earlier out-of-memory condition, causing Denial of Service impact.

Product is only affected if IEC 61850 functionality is configured.

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

Solution

Upgrade the RTU500 series CMU firmware to a fixed version (13.8.2, or 13.7.9 / 12.7.8 depending on the installed branch as listed in the Hitachi Energy advisory) and apply the general mitigation factors and workarounds described in the advisory.

See Also

http://www.nessus.org/u?d21730e8

https://www.cisa.gov/news-events/ics-advisories/icsa-26-155-04

Plugin Details

Severity: Medium

ID: 505376

File Name: tenable_ot_abb_CVE-2026-32778.nasl

Version: 1.1

Type: Remote

Family: Tenable.ot

Published: 6/17/2026

Updated: 6/17/2026

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 3.6

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:hitachienergy:rtu520_firmware:13.8.1, cpe:/o:hitachienergy:rtu530_firmware:13.8.1, cpe:/o:hitachienergy:rtu540_firmware:13.8.1, cpe:/o:hitachienergy:rtu560_firmware:13.8.1, cpe:/o:hitachienergy:rtu530_firmware:13.6, cpe:/o:hitachienergy:rtu530_firmware:13.7, cpe:/o:hitachienergy:rtu560_firmware:13.5, cpe:/o:hitachienergy:rtu540_firmware:13.5, cpe:/o:hitachienergy:rtu560_firmware:13.7, cpe:/o:hitachienergy:rtu520_firmware:13.7, cpe:/o:hitachienergy:rtu530_firmware:13.5, cpe:/o:hitachienergy:rtu540_firmware:13.6, cpe:/o:hitachienergy:rtu520_firmware:13.6, cpe:/o:hitachienergy:rtu520_firmware:13.5, cpe:/o:hitachienergy:rtu560_firmware:13.6, cpe:/o:hitachienergy:rtu540_firmware:13.7

Required KB Items: Tenable.ot/ABB

Patch Publication Date: 5/26/2026

Vulnerability Publication Date: 5/26/2026

Reference Information

CVE: CVE-2026-32778

CWE: 476

ICSA: 26-155-04