CVE-2026-66369

Medium

Description

The GOOSE parser contains an off-by-one boundary-handling flaw that can be triggered by a single unauthenticated Layer-2 multicast frame on the process bus. When specific GOOSE message fields are processed, the parser advances its internal buffer position incorrectly, resulting in a heap out-of-bounds read. On affected platforms, this condition reliably terminates the subscriber process and causes a denial-of-service.

SeverityMedium
CVSS6.5
Exploit probability—
ProductMz Automation Gmbh Libiec61850
PublishedJul 30, 2026
First seenJul 30, 2026

How to fix

Update
  • MZ Automation GmbH libiec618501.6.2 or later

Affected products

ProductAffected versionsFixed in
MZ Automation GmbH libiec61850v < 1.6.21.6.2

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