---
id: CVE-2026-111732
title: Out-of-bounds write when parsing AR Vendor Block requests
summary: >-
  P-Net before 1.0.3, when built with PNET_OPTION_AR_VENDOR_BLOCKS enabled,
  parses a data length from a field of the ARVendorBlock request that is not
  part of the block definition and uses it as the number of bytes to copy into a
  fixed-siz…
severity: critical
cvss: 9.3
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'
cvssSource: cna
cwe:
  - CWE-787
vendor: RT-Labs
product: P-Net
affected:
  - P-Net < 1.0.3
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-11-05T21:21:27.474782Z'
published: '2026-10-29'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T21:21:46.023Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-111732'
references:
  - url: 'https://rt-labs.com/wp-content/uploads/2026/10/RRTL-261019-01.pdf'
    label: Cybersecurity advisory for P-Net
tags:
  - cve.org
epss: 0.00404
epssPercentile: 0.34891
ingestedAt: '2026-11-01T20:00:16.972Z'
---

## Overview

P-Net before 1.0.3, when built with PNET_OPTION_AR_VENDOR_BLOCKS enabled, parses a data length from a field of the ARVendorBlock request that is not part of the block definition and uses it as the number of bytes to copy into a fixed-size buffer, without comparing it with the buffer size or the block length. A crafted Connect request causes an out-of-bounds write. This can lead to a crash (denial of service) or potentially arbitrary code execution.



This option is disabled by default.

## Affected

- `P-Net < 1.0.3`

## Remediation

Upgrade to P-Net 1.0.3 or later.