What is CVE-2026-66720?

CVE-2026-66720 is a medium-severity vulnerability in Mz Automation Gmbh Libiec61850, classified under Out-of-bounds Read. CVSS score: 6.5/10. Published 2026-07-30.

How severe is CVE-2026-66720?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Out-of-bounds Read in Mz Automation Gmbh Libiec61850

CVE-2026-66720

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.

Vulnerability class: Buffer Overflow

EPSS: 0.002 (7.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Mz Automation Gmbh Libiec61850 — versions 0, 1.6.2

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

Frequently asked questions

What is CVE-2026-66720?: CVE-2026-66720 is a medium-severity vulnerability in Mz Automation Gmbh Libiec61850, classified under Out-of-bounds Read. CVSS score: 6.5/10. Published 2026-07-30.
How severe is CVE-2026-66720?: Medium severity. CVSS v3 base score is 6.5 out of 10.