CVE-2026-66720CWE-125

CVE-2026-66720

Medium · published July 31, 2026

CVSS v3.1
6.5
EPSS
0%
Percentile
19.9
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
6.5 · MEDIUM
Vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00285 · 19.9th percentile
Weakness
CWE-125 · Out-of-bounds Read
Published
2026-07-31T03:16Z
References (2)
https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-211-10.json · [email protected]https://www.cisa.gov/news-events/ics-advisories/icsa-26-211-10 · [email protected]
EPSS history
Timeline
  • 30 JUL 22:46Z
    MZ Automation libiec61850 Out-of-bounds Read
    cvelistv5