Vulnerability · Published Jul 30, 2026 · Assigned by icscert

CVE-2026-66720MZ Automation libiec61850 Out-of-bounds Read

Medium 6.5

In plain English

A medium-severity out-of-bounds read in libiec61850 from MZ Automation GmbH. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities).

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.3%top 78.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
MZ Automation GmbH	libiec61850	0 – before 1.6.2

Weakness: CWE-125 · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

In plain English

Official description

Affected products (as reported)

References