Heap Out-of-Bounds Read in GOOSE Subscriber Component of IEC 61850 by Vendor
CVE-2026-66720

7.1HIGH

Key Information:

Vendor

Mz Automation Gmbh

Status
Libiec61850
Vendor
CVE Published:
30 July 2026

What is CVE-2026-66720?

The GOOSE subscriber component fails to properly validate the UTC timestamp field in unauthenticated IEC 61850 GOOSE Layer-2 multicast messages. When a malformed GOOSE frame is processed, it can lead to a heap out-of-bounds read, resulting in the crash of the process. This vulnerability can potentially cause a denial-of-service condition, affecting the reliability of networked systems that rely on IEC 61850 communication for operation.

Affected Version(s)

libiec61850 0 < 1.6.2

libiec61850 1.6.2

References

https://www.cisa.gov/news-events/ics-advisories/icsa-26-2...
https://github.com/cisagov/CSAF/blob/develop/csaf_files/O...

CVSS V4

Score:
7.1
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Adjacent Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Arun Babu of Central Power Research Institute reported this vulnerability to CISA.
.