CVE-2026-66720: MZ Automation libiec61850 · Out-of-bounds Read
Affects MZ Automation libiec61850Source CVE Database V5
Not known to be exploited · CVSS 6.5 Medium : upgrade to 1.6.2 when convenient.
Data as of 29 Oct 2026, 07:15 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 20% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.6.2
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 30 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade MZ Automation libiec61850 to 1.6.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| MZ Automation GmbHlibiec61850 | Affected
| Fixed in
|
AI-suggested
If you cannot patch yet, consider restricting network access to the affected GOOSE multicast traffic or deploying network-level filtering to block malformed frames if feasible.
Description
CVE-2026-66720 is a medium severity vulnerability in MZ Automation GmbH's libiec61850 library. The flaw exists in the GOOSE subscriber component, which improperly validates the UTC timestamp field in unauthenticated IEC 61850 GOOSE Layer-2 multicast messages. A specially crafted GOOSE frame with an undersized timestamp field can cause a heap out-of-bounds read, leading to a process crash and denial-of-service condition.