MZ Automation libiec61850 up to 1.6.1 GOOSE parser off-by-one

CVSS Meta Temp Score
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CTI Interest Score
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7.0$0-$5k1.70

Summaryinfo

A vulnerability was found in MZ Automation libiec61850 up to 1.6.1. It has been classified as critical. Affected is an unknown function of the component GOOSE parser. The manipulation leads to off-by-one. This vulnerability is uniquely identified as CVE-2026-66369. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as critical, has been found in MZ Automation libiec61850 up to 1.6.1. This issue affects an unknown code block of the component GOOSE parser. The manipulation with an unknown input leads to a off-by-one vulnerability. Using CWE to declare the problem leads to CWE-193. A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

The GOOSE parser contains an off-by-one boundary-handling flaw that can be triggered by a single unauthenticated Layer-2 multicast frame on the process bus. When specific GOOSE message fields are processed, the parser advances its internal buffer position incorrectly, resulting in a heap out-of-bounds read. On affected platforms, this condition reliably terminates the subscriber process and causes a denial-of-service.

The advisory is shared at cisa.gov. The identification of this vulnerability is CVE-2026-66369 since 07/27/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available.

Upgrading to version 1.6.2 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 7.0

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
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: Off-by-one
CWE: CWE-193 / CWE-189
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-2026-66369 (🔒)
GCVE (CVE): GCVE-0-2026-66369
GCVE (VulDB): GCVE-100-384977

Entryinfo

Created: 07/31/2026 01:30
Changes: 07/31/2026 01:30 (55)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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