# CVE-2026-68906: libIEC61850 infinite loop in ACSE parseUserInformation

Source: https://junglewise.ai/threats/cve-2026-68906-libiec61850-is-an-open-source-implementation-of-iec-61850-client  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-16. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-68906 · Severity: info · Published 2026-10-16

libIEC61850 is a library implementing industrial control protocols used in power systems and critical infrastructure. A remote attacker can crash or cause severe CPU consumption by sending a specially crafted network message during the initial connection phase, disrupting critical infrastructure operations.

Technologies: [MZ Automation libIEC61850](https://junglewise.ai/threats/technologies/libiec61850). Vendors: [MZ Automation](https://junglewise.ai/threats/vendors/mz-automation).

## Quick answers

**Is CVE-2026-68906 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-68906 being exploited in the wild.

**How severe is CVE-2026-68906?** Informational severity, published 16 October 2026.

**Which products and versions are affected?** MZ Automation libIEC61850 before 1.6.2.

**Is there a fix for CVE-2026-68906?** Yes: fixed in 1.6.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-68906 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-68906?** Check whether you run MZ Automation libIEC61850 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 1.6.2

## Technical details

The vulnerability is an infinite loop and out-of-bounds read in the ACSE parseUserInformation function in acse.c. When parsing a truncated long-form length field in an AARE PDU, the code checks for zero length before validating a negative buffer position, allowing an infinite parsing loop or one-byte out-of-bounds memory access when the preceding byte is inaccessible. An unauthenticated remote peer can trigger this via a malformed AARE PDU during association.

## Affected products

- mz-automation libIEC61850 before 1.6.2

## Timeline

- 2026-10-16: disclosed

## References

- [https://github.com/mz-automation/libiec61850/commit/2edf2a12bf0ced6a2ac595862e3e873814983f7f](https://github.com/mz-automation/libiec61850/commit/2edf2a12bf0ced6a2ac595862e3e873814983f7f)
- [https://github.com/mz-automation/libiec61850/releases/tag/v1.6.2](https://github.com/mz-automation/libiec61850/releases/tag/v1.6.2)

## Related threats

- [libIEC61850 invalid free in MMS report serialization](https://junglewise.ai/threats/cve-2026-68908-libiec61850-is-an-open-source-implementation-of-iec-61850-client)
- [libIEC61850 buffer over-read in dataset access handler](https://junglewise.ai/threats/cve-2026-68907-libiec61850-is-an-open-source-implementation-of-iec-61850-client)
- [libIEC61850 MMS ObtainFile double-free denial of service](https://junglewise.ai/threats/cve-2026-57446-libiec61850-is-an-open-source-implementation-of-iec-61850-client)
- [libIEC61850 NULL pointer dereference in MMS read service](https://junglewise.ai/threats/cve-2026-48741-libiec61850-is-an-open-source-implementation-of-iec-61850-client)
- [libIEC61850 MMS file service information disclosure](https://junglewise.ai/threats/cve-2026-48503-libiec61850-is-an-open-source-implementation-of-iec-61850-client)