# CVE-2026-48741: libIEC61850 NULL pointer dereference in MMS read service

Source: https://junglewise.ai/threats/cve-2026-48741-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-2026-48741 · Severity: high · CVSS 7.5 · Published 2026-10-16

libIEC61850 is a library that implements industrial power grid communication protocols (IEC 61850). A flaw in the MMS read service fails to validate array ranges, allowing a remote attacker to send a crafted message that crashes servers with array-containing data models, potentially causing grid communication outages.

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

## Quick answers

**Is CVE-2026-48741 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-48741 being exploited in the wild.

**How severe is CVE-2026-48741?** High severity, with a CVSS score of 7.5, published 16 October 2026.

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

**Is there a fix for CVE-2026-48741?** 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-2026-48741 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-48741?** 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 alternateArrayAccess function in mms_read_service.c does not validate alternate-access sub-array ranges when numberOfElements exceeds zero, causing MmsValue_getElement to return NULL. This NULL pointer is then passed to MmsValue_isDeletable without a null check, triggering a NULL pointer dereference. A remote attacker can send a malicious MMS Read request over the network to crash an affected server, while the single-element error path handles invalid indices safely.

## Affected products

- mz-automation libIEC61850 before 1.6.2

## Timeline

- 2026-10-16: disclosed

## References

- [https://github.com/mz-automation/libiec61850/commit/7c15310405def00cac628ebde4ce1404bfb8a411](https://github.com/mz-automation/libiec61850/commit/7c15310405def00cac628ebde4ce1404bfb8a411)
- [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 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 MMS file service information disclosure](https://junglewise.ai/threats/cve-2026-48503-libiec61850-is-an-open-source-implementation-of-iec-61850-client)