# CVE-2026-57446: libIEC61850 MMS ObtainFile double-free denial of service

Source: https://junglewise.ai/threats/cve-2026-57446-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-2026-57446 · Severity: medium · CVSS 5.3 · Published 2026-10-16

libIEC61850 is a library implementing IEC 61850 industrial power systems protocols used in electrical substations and grid infrastructure. A flaw in the MMS ObtainFile service allows a remote attacker to crash a vulnerable server by sending a specific sequence of file requests, causing the system to attempt to free the same memory block twice. This can disrupt critical power system communications and 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-2026-57446 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-57446 being exploited in the wild.

**How severe is CVE-2026-57446?** Medium severity, with a CVSS score of 5.3, published 16 October 2026.

**Which products and versions are affected?** MZ Automation libIEC61850 1.6.1 to before 1.6.2.

**Is there a fix for CVE-2026-57446?** 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-2026-57446 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-57446?** 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

A double-free vulnerability exists in the MMS ObtainFile service when a successful file download operation closes a file handle but leaves a stale pointer in a task structure marked as unused. If a subsequent ObtainFile request reuses that task and destination creation fails, the cleanup code attempts to close the already-freed FILE object again. The vulnerability requires network access to the MMS service and can be triggered remotely without authentication.

## Affected products

- mz-automation libIEC61850 1.6.1 to before 1.6.2

## Timeline

- 2026-10-16: disclosed

## References

- [https://github.com/mz-automation/libiec61850/commit/d86b4a9c7a903641819235e1678b18901518f3cd](https://github.com/mz-automation/libiec61850/commit/d86b4a9c7a903641819235e1678b18901518f3cd)
- [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 infinite loop in ACSE parseUserInformation](https://junglewise.ai/threats/cve-2026-68906-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)