---
id: CVE-2026-48741
title: >-
  libIEC61850: Remote NULL dereference in MMS Read alternate-access sub-array
  path leads to server-side DoS
summary: >-
  libIEC61850 is an open-source implementation of IEC 61850 client and server
  protocols including MMS, GOOSE, Sampled Values, and R-Session. Prior to 1.6.2,
  alternateArrayAccess in src/mms/iso_mms/server/mms_read_service.c does not
  validat…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-129
  - CWE-252
  - CWE-476
  - CWE-754
vendor: mz-automation
product: libiec61850
affected:
  - libiec61850 < 1.6.2
published: '2026-10-16'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:45:32.680Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-48741'
references:
  - url: >-
      https://github.com/mz-automation/libiec61850/security/advisories/GHSA-8mfr-hq64-9w33
    label: >-
      https://github.com/mz-automation/libiec61850/security/advisories/GHSA-8mfr-hq64-9w33
  - url: >-
      https://github.com/mz-automation/libiec61850/commit/7c15310405def00cac628ebde4ce1404bfb8a411
    label: >-
      https://github.com/mz-automation/libiec61850/commit/7c15310405def00cac628ebde4ce1404bfb8a411
  - url: 'https://github.com/mz-automation/libiec61850/releases/tag/v1.6.2'
    label: 'https://github.com/mz-automation/libiec61850/releases/tag/v1.6.2'
tags:
  - cve.org
ingestedAt: '2026-10-16T17:24:46.829Z'
---

## Overview

libIEC61850 is an open-source implementation of IEC 61850 client and server protocols including MMS, GOOSE, Sampled Values, and R-Session. Prior to 1.6.2, alternateArrayAccess in src/mms/iso_mms/server/mms_read_service.c does not validate an alternate-access sub-array range when numberOfElements is greater than zero. An out-of-range MmsValue_getElement call returns NULL, and the sub-array branch passes that value to MmsValue_isDeletable, causing a NULL pointer dereference. A remote MMS Read request can therefore crash servers whose data models contain arrays, while the single-element error path handles the same invalid index safely. This issue is fixed in version 1.6.2.

## Affected

- `libiec61850 < 1.6.2`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.