---
id: "CVE-2026-103672"
kind: "vulnerability"
aliases: ["CVE-2026-103672"]
title: "PEAK-System PCAN parser: unchecked DLC overflows a stack buffer"
severity: "high"
cvss: 7.1
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "PEAK-System Device Driver Setup", "fixed": ["5.1.4"], "affected": "<= 5.1.2.1151", "ecosystem": "vendor"}, {"name": "PCAN Windows CAN device drivers", "fixed": ["5.1.4"], "affected": "<= 5.1.2", "ecosystem": "vendor"}]
ecosystems: []
tags: ["can-bus", "hms-networks", "ics", "infrastructure", "kernel-driver", "local", "pcan", "peak-system", "windows"]
not_affected_if: ["linux", "no-pcan-driver-installed", "version-5.1.4-or-later"]
published_at: "2026-10-20T21:17:14+00:00"
first_seen_at: "2026-10-23T21:57:21+00:00"
updated_at: "2026-10-25T03:35:55+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-103672", "first_seen_at": "2026-10-23T21:57:21+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-10-25T03:35:55+00:00"}]
---

# PEAK-System PCAN parser: unchecked DLC overflows a stack buffer

The PEAK-System PCAN parser uses an attacker-supplied DLC value to index a length table without checking that it is 0x0f or less. The payload is then copied into a fixed-size stack buffer, which can overflow and may let an attacker run code.

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

## Affected

- vendor:PEAK-System Device Driver Setup affected <= 5.1.2.1151 fixed 5.1.4
- vendor:PCAN Windows CAN device drivers affected <= 5.1.2 fixed 5.1.4

## How to check

On Windows, check the installed PEAK-System Device Driver Setup version (Programs and Features) and the PCAN driver version in Device Manager. Affected if Setup <= 5.1.2.1151 or PCAN driver <= 5.1.2; 5.1.4 is fixed.

## Fix

Upgrade to PEAK-System PCAN Windows driver / Device Driver Setup 5.1.4 or newer (https://www.peak-system.com/support/downloads/software/).

## Timeline

- 2026-10-23T21:57:21+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-103672
- 2026-10-25T03:35:55+00:00 analyst — CISA ICSA-26-293-01 (republishing HMS Networks CSAF): affects PEAK-System Device Driver Setup <=5.1.2.1151 and PCAN Windows drivers <=5.1.2; fixed in 5.1.4. Local low-priv, kernel driver stack overflow (CWE-129); no exploitation or PoC seen; did not read HMS's own advisory page, so nothing marked verified. Social search skipped (no public conversation expected).

## Documents

- [advisory] CISA ICSA-26-293-01 HMS Networks PEAK-System PCAN Windows drivers https://www.cisa.gov/news-events/ics-advisories/icsa-26-293-01
- [mentions] OpenCVE CVE-2026-103672 https://app.opencve.io/cve/CVE-2026-103672

## From the sources

The PEAK-System PCAN parser indexes a length table using attacker-controlled DLC without enforcing DLC <= 0x0f, then copies attacker payload from record+0x1c into a fixed-size stack destination.

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