---
id: "CVE-2026-57446"
kind: "vulnerability"
aliases: ["CVE-2026-57446"]
title: "libIEC61850: double-close of a file handle lets remote clients crash servers"
severity: "medium"
cvss: 5.3
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["energy", "iec-61850", "industrial-control", "libiec61850", "package", "scada"]
not_affected_if: ["default-config", "no-mms-file-service"]
published_at: "2026-10-16T16:18:44+00:00"
first_seen_at: "2026-10-23T21:57:13+00:00"
updated_at: "2026-10-25T04:27:16+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-57446", "first_seen_at": "2026-10-23T21:57:13+00:00"}]
---

# libIEC61850: double-close of a file handle lets remote clients crash servers

libIEC61850 versions 1.6.1 through 1.6.2 close a file handle twice after a crafted sequence of MMS ObtainFile requests. A remote client can crash a server that has the MMS file service and ObtainFile enabled.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the libIEC61850 version in the build or in the vendored source; affected versions are 1.6.1 up to but not including `1.6.2`.
- Check whether the server enables the MMS file service and ObtainFile handling in its configuration (unknown which setting name the sources use).

## Fix

- Upgrade libIEC61850 to `1.6.2` or later.

## Timeline

- 2026-10-23T21:57:13+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-57446

## From the sources

libIEC61850 is an open-source implementation of IEC 61850 client and server protocols including MMS, GOOSE, Sampled Values, and R-Session. From 1.6.1 until 1.6.2, a successful MMS ObtainFile operation closes MmsObtainFileTask::fileHandle but leaves the stale non-NULL value in a task marked MMS_FILE_UPLOAD_STATE_NOT_USED. If a later ObtainFile request reuses that task and destination creation fails, MMS_FILE_UPLOAD_STATE_SEND_OBTAIN_FILE_ERROR_DESTINATION cleanup closes the stale FILE object again. Servers with the MMS file service and ObtainFile enabled can therefore be crashed remotely by the success-then-failure request sequence. This issue is fixed in version 1.6.2.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_