# CVE-2026-111735: Integer underflow leads to out-of-bounds read in pf_cpm_c_data_ind()


- **Severity:** High 7.1 (`CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/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-pmgf-c5w3-wm94

## What is CVE-2026-111735?

CVE-2026-111735 is a high-severity vulnerability in RT-Labs P-Net, published on 29 Oct 2026. 

### Official description

P-Net before 1.0.3 contains an integer underflow in pf_cpm_c_data_ind(). When handling a received cyclic data frame while the consumer is in the FRUN or RUN state, the offset of the APDU status was computed as the frame length minus 4 using 16-bit arithmetic, without checking that the frame is long enough. A crafted short frame makes the offset wrap around, so the function reads outside the receive buffer. This can cause a crash (denial of service) or disclose memory content.

Weakness: CWE-191 (Integer Underflow (Wrap or Wraparound)), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-111735?


## How do I fix CVE-2026-111735?

No fix has been published for CVE-2026-111735 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-111735 being exploited?

There is no known exploitation of CVE-2026-111735 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-111735 and fix it if it is affected.

What it is: CVE-2026-111735 is a high-severity vulnerability in RT-Labs P-Net, published on 29 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-111735 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-2026-111735/ (Markdown: https://insights.sbomify.com/CVE-2026-111735/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-111735
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-111735
- OSV: https://osv.dev/vulnerability/CVE-2026-111735

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-111735/
Summaries are generated and may contain mistakes; the official description above is the record.