CVE-2026-66349: Mz Automation GmbH LIBIEC61850

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

The MMS server connection handler contains a flaw in its processing of BER-encoded request data. When an MMS confirmed request PDU containing an extended BER tag is received over an established session, the decoder may advance its internal buffer incorrectly due to a missing bounds check. This results in a one byte heap out-of-bounds read and causes the MMS service process to terminate, leading to a denial-of-service condition.

Affected products

• Mz Automation GmbH LIBIEC61850: before 1.6.2 (fixed in 1.6.2)

Published 2026-07-30. Last modified 2026-09-08.