MZ Automation libIEC61850 up to 1.6.1 src/mms/iso_acse/acse.c parseUserInformation out-of-bounds

Summaryinfo

A vulnerability described as critical has been identified in MZ Automation libIEC61850 up to 1.6.1. The affected element is the function parseUserInformation of the file src/mms/iso_acse/acse.c. Such manipulation leads to out-of-bounds. This vulnerability is listed as CVE-2026-68906. The attack may be performed from remote. There is no available exploit. Upgrading the affected component is recommended.

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 the function parseUserInformation of the file src/mms/iso_acse/acse.c. The manipulation with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

libIEC61850 is an open-source implementation of IEC 61850 client and server protocols including MMS, GOOSE, Sampled Values, and R-Session. Prior to 1.6.2, parseUserInformation in src/mms/iso_acse/acse.c checks len for zero before validating the negative bufPos returned by BerDecoder_decodeLength for a truncated long-form length. The continue path therefore swallows the error, reads buffer[-1], resets parsing to the beginning, and repeats the same malformed state. An unauthenticated remote peer can send a malformed AARE PDU during association to cause an infinite CPU loop under a normal allocator or a one-byte out-of-bounds read and process abort when the preceding byte is inaccessible. This issue is fixed in version 1.6.2.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-68906 since 07/31/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. 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

• Automation Software

Vendor

• MZ Automation

Name

• libIEC61850

Version

• 1.6.0
• 1.6.1

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CPE 2.2info

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