MZ Automation libiec61850 up to 1.6.1 MMS BER decoder length heap-based overflow

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.0$0-$5k0.85

Summaryinfo

A vulnerability labeled as critical has been found in MZ Automation libiec61850 up to 1.6.1. Affected by this issue is some unknown functionality of the component MMS BER decoder. Such manipulation of the argument length leads to heap-based overflow. This vulnerability is listed as CVE-2026-65421. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability, which was classified as critical, has been found in MZ Automation libiec61850 up to 1.6.1. Affected by this issue is an unknown part of the component MMS BER decoder. The manipulation of the argument length with an unknown input leads to a heap-based overflow vulnerability. Using CWE to declare the problem leads to CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). Impacted is confidentiality, integrity, and availability. CVE summarizes:

The MMS BER decoder contains a flaw in decoding fixed-width BER fields (boolean/integer): an attacker-supplied length value is not validated, causing a read past the end of a heap buffer. This leads to termination of the MMS service process and a denial-of-service condition.

The advisory is shared for download at cisa.gov. This vulnerability is handled as CVE-2026-65421 since 07/27/2026. The exploitation is known to be easy. The attack may be launched remotely. There are known technical details, but no exploit is available.

Upgrading to version 1.6.2 eliminates this vulnerability.

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Productinfo

Type

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: libiec61850 1.6.2

Timelineinfo

07/27/2026 CVE reserved
07/30/2026 +3 days VulDB entry created
07/31/2026 +0 days Advisory disclosed
07/31/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: cisa.gov
Status: Confirmed

CVE: CVE-2026-65421 (🔒)
GCVE (CVE): GCVE-0-2026-65421
GCVE (VulDB): GCVE-100-384968

Entryinfo

Created: 07/31/2026 00:55
Changes: 07/31/2026 00:55 (56)
Complete: 🔍
Cache ID: 216::103

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