CVE-2026-66360

MZ Automation libiec61850 Out-of-bounds Read

Assigner: icscert
Reserved: 27.07.2026 Published: 30.07.2026 Updated: 30.07.2026

The ISO Presentation layer contains a flaw in the handling of specific parameters during normal mode negotiation. A missing length check in the processing of the encoded presentation data allows an attacker controlled field with a zero length value to trigger a bounded heap over read. This condition occurs before MMS session establishment, a crafted TCP/102 connection attempt can trigger the issue. The resulting over read causes the process to terminate, leading to a denial of service condition.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 7.5

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	None
User Interaction	None	Availability Impact	High

CVSS 3.1

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.7

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	MZ Automation GmbH
Product	libiec61850
Versions	Default: unaffected affected from 0 to 1.6.2 (excl.) Version 1.6.2 is unaffected

Vendor

MZ Automation GmbH

Product

libiec61850

Versions

Default: unaffected

affected from 0 to 1.6.2 (excl.)
Version 1.6.2 is unaffected

Solutions

MZ Automation GmbH recommends that users update to version 1.6.2.

Credits

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

References

Problem Types

CWE-125 CWE