# CVE-2026-111731: Infinite loop when reading PDPortDataCheck record of subslot 0


- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 29 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-9m2p-fcvq-hxrv

## What is CVE-2026-111731?

CVE-2026-111731 is a high-severity vulnerability in RT-Labs P-Net, published on 29 Oct 2026. 

### Official description

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.

Weakness: CWE-835 (Loop with Unreachable Exit Condition)

## Which versions are affected by CVE-2026-111731?


## How do I fix CVE-2026-111731?

No fix has been published for CVE-2026-111731 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-111731 being exploited?

There is no known exploitation of CVE-2026-111731 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-111731 and fix it if it is affected.

What it is: CVE-2026-111731 is a high-severity vulnerability in RT-Labs P-Net, published on 29 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-111731 in the wild and no public exploit code.

Affected product: RT-Labs P-Net. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-111731/ (Markdown: https://insights.sbomify.com/CVE-2026-111731/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-111731
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-111731
- OSV: https://osv.dev/vulnerability/CVE-2026-111731

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-111731/
Summaries are generated and may contain mistakes; the official description above is the record.