CVE-2026-66349: CWE-125 in MZ Automation GmbH libiec61850
A vulnerability in the MMS server connection handler of MZ Automation GmbH's libiec61850 library causes a heap out-of-bounds read when processing BER-encoded request data with an extended BER tag. This flaw leads to the termination of the MMS service process, resulting in a denial-of-service condition. No patch or official remediation has been confirmed yet.
AI Analysis
Technical Summary
CVE-2026-66349 is a medium severity vulnerability (CVSS 6.5) in the libiec61850 library by MZ Automation GmbH. The flaw exists in the MMS server connection handler's processing of BER-encoded request data. Specifically, when an MMS confirmed request PDU containing an extended BER tag is received, the decoder may incorrectly advance its internal buffer due to a missing bounds check. This causes a one-byte heap out-of-bounds read, which terminates the MMS service process and causes denial of service. There is no vendor advisory or patch information currently available.
Potential Impact
The vulnerability causes a denial-of-service condition by crashing the MMS service process upon receiving a specially crafted MMS confirmed request PDU with an extended BER tag. There is no impact on confidentiality or integrity reported.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider restricting access to the MMS service to trusted entities and monitor for unusual service terminations.
CVE-2026-66349: CWE-125 in MZ Automation GmbH libiec61850
Description
A vulnerability in the MMS server connection handler of MZ Automation GmbH's libiec61850 library causes a heap out-of-bounds read when processing BER-encoded request data with an extended BER tag. This flaw leads to the termination of the MMS service process, resulting in a denial-of-service condition. No patch or official remediation has been confirmed yet.
CVSS v3.1
Score 6.5medium
Affected software
MZ Automation GmbH
libiec61850
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-66349 is a medium severity vulnerability (CVSS 6.5) in the libiec61850 library by MZ Automation GmbH. The flaw exists in the MMS server connection handler's processing of BER-encoded request data. Specifically, when an MMS confirmed request PDU containing an extended BER tag is received, the decoder may incorrectly advance its internal buffer due to a missing bounds check. This causes a one-byte heap out-of-bounds read, which terminates the MMS service process and causes denial of service. There is no vendor advisory or patch information currently available.
Potential Impact
The vulnerability causes a denial-of-service condition by crashing the MMS service process upon receiving a specially crafted MMS confirmed request PDU with an extended BER tag. There is no impact on confidentiality or integrity reported.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider restricting access to the MMS service to trusted entities and monitor for unusual service terminations.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- icscert
- Date Reserved
- 2026-07-27T19:32:49.401Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a6bd5b69c2644c7f8d19678
Added to database: 07/30/2026, 22:52:38 UTC
Last enriched: 08/07/2026, 14:51:52 UTC
Last updated: 09/13/2026, 10:01:32 UTC
Views: 59
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