---
id: "CVE-2026-111731"
kind: "vulnerability"
aliases: ["CVE-2026-111731"]
title: "P-Net: infinite loop on a PROFINET read request halts the device"
severity: "high"
cvss: 8.7
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["embedded", "industrial-control", "infrastructure", "p-net", "profinet"]
not_affected_if: ["no-profinet-exposure", "p-net-1.0.3-or-later"]
published_at: "2026-10-29T16:17:57+00:00"
first_seen_at: "2026-10-29T16:25:56+00:00"
updated_at: "2026-10-29T16:29:25+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-111731", "first_seen_at": "2026-10-29T16:25:56+00:00"}]
---

# P-Net: infinite loop on a PROFINET read request halts the device

P-Net, a PROFINET device stack, loops forever when it handles a read request for the PDPortDataCheck record on subslot 0 (the whole module). The device stops responding, so an unauthenticated remote attacker can cause a denial of service.

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

## How to check

- Check the P-Net version the device firmware is built on; the sources say versions before `1.0.3` are affected
- Confirm whether the device is reachable from networks that send PROFINET read requests

## Fix

- Move P-Net to `1.0.3` or later

## Timeline

- 2026-10-29T16:25:56+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-111731

## From the sources

P-Net before 1.0.3 enters an infinite loop when handling a read request for the PDPortDataCheck record with subslot 0 (whole module). The loop over the ports never advanced to the next port, so the request never completes and the device stops responding. A remote unauthenticated attacker can use this to cause a denial of service.

---

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