CVE-2026-66720

MZ Automation libiec61850 Out-of-bounds Read

Published Jul 30, 2026 CVSS 4.0 · 7.1 High EPSS < 1% KEV · Not listed
Description
The GOOSE subscriber component improperly validates the UTC timestamp
field in unauthenticated IEC 61850 GOOSE (EtherType 0x88B8) Layer-2
multicast messages. A specially crafted GOOSE frame containing an
undersized timestamp field can trigger a heap out-of-bounds read during
message processing, causing the process to crash and resulting in a
denial-of-service condition.

Remediation

Vendor Solution

MZ Automation GmbH recommends that users update to version 1.6.2.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Mz-automation
Mz-automation libiec61850
Vendors & Products Mz-automation
Mz-automation libiec61850
Type Values Removed Values Added
Description The GOOSE subscriber component improperly validates the UTC timestamp field in unauthenticated IEC 61850 GOOSE (EtherType 0x88B8) Layer-2 multicast messages. A specially crafted GOOSE frame containing an undersized timestamp field can trigger a heap out-of-bounds read during message processing, causing the process to crash and resulting in a denial-of-service condition.
Title MZ Automation libiec61850 Out-of-bounds Read
Weaknesses CWE-125
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
icscert
Published
Updated
Jul 31, 2026, 3:58 PM
Reserved
Jul 27, 2026, 7:32 PM
Status
Deferred
Published
Jul 30, 2026, 11:16 PM
Modified
Sep 3, 2026, 5:58 PM