# Belden macmon, NRSW critical RCE flaws

Published: 2026-11-02 · Severity: severe · Sectors: Infrastructure, Manufacturing
Canonical: https://vorant.io/reports/f84ca571-f21b-53d3-843f-f8d4e650ae79/belden-macmon-nrsw-critical-rce-flaws
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> CERT-FR warns of critical PHP vulnerabilities in Belden macmon and NRSW allowing remote code execution; patches available.

Source: cert.cyber.gouv.fr — https://www.cert.cyber.gouv.fr/avis/CERTFR-2026-AVI-1438

## What to check

- Applies to: The 2 CVEs named below. Whether you run an affected version is not assessed: check the versions the source lists.
- Exploitation: CISA lists CVE-2026-109618 and CVE-2026-109619 as exploited in the wild.

CERT-FR has issued an advisory covering multiple critical vulnerabilities in Belden's macmon network access control product and NRSW software, stemming from PHP-related flaws. The vulnerabilities, tracked as CVE-2026-109618 and CVE-2026-109619, allow an attacker to achieve remote arbitrary code execution. Affected systems include NRSW versions prior to 5.0.0.104 and macmon versions 6.x and 7.x that have not received the latest Belden security patch.

Belden notes that organizations running macmon 6.x must first upgrade to 7.x before the latest security patch can be applied. This advisory follows an earlier CERT-FR alert (CERTFR-2026-ALE-014) published the previous day, suggesting heightened urgency or possible active concern around these flaws. Defenders operating Belden macmon or NRSW, commonly used in industrial and enterprise network access control contexts, should prioritize patching per the vendor's security bulletin referenced in the documentation.

No specific in-the-wild exploitation is confirmed in this advisory, but the classification as critical by Belden's own PSIRT and the prior escalation to a CERT-FR alert indicate these flaws warrant prompt remediation.

## Mentioned in this report

- Vulnerabilities: CVE-2026-109618 (KEV), CVE-2026-109619 (KEV)

Source reporting: https://www.cert.cyber.gouv.fr/avis/CERTFR-2026-AVI-1438

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