GOOSE subscriber crash via undersized timestamp
Published Jul 30, 2026 · Updated Jul 30, 2026
Out-of-bounds read in MZ Automation GmbH libIEC61850 before 1.6.2 allows attackers to crash GOOSE subscriber processes. The GOOSE subscriber accepts an undersized UTC timestamp in an IEC 61850 GOOSE frame, then reads beyond the heap buffer while processing the timestamp field. Unauthenticated access to the same Layer-2 segment is required to send EtherType 0x88B8 multicast traffic; the bounded consequence is a subscriber-process crash and service interruption.
Summary
What happened
Out-of-bounds read in MZ Automation GmbH libIEC61850 before 1.6.2 allows attackers to crash GOOSE subscriber processes. The GOOSE subscriber accepts an undersized UTC timestamp in an IEC 61850 GOOSE frame, then reads beyond the heap buffer while processing the timestamp field. Unauthenticated access to the same Layer-2 segment is required to send EtherType 0x88B8 multicast traffic; the bounded consequence is a subscriber-process crash and service interruption.
The record
- CVE
- CVE-2026-66720
- Published
- Jul 30, 2026
- Updated
- Jul 30, 2026
- Vendor
- MZ Automation GmbH
- Product
- libIEC61850
- Classifications
- CWE-125, T1499
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 30, 2026CVE publishedPublication date reported by the CVE source.
- Jul 30, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=0 <1.6.2
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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