# Lantronix G520 gateway flaws enable root code execution

Published: 2026-09-29 · Severity: routine · Sectors: transportation, energy, infrastructure
Canonical: https://vorant.io/reports/b777c2ab-062d-5df0-800c-46db384f82c7/lantronix-g520-gateway-flaws-enable-root-code-execution

> Two Lantronix G520 Series Cellular Gateway vulnerabilities allow attackers to spoof firmware updates and execute arbitrary code as root; patch to 2.6.0.7R6.

CISA published an ICS advisory for the Lantronix G520 Series Cellular Gateway, a cellular gateway device deployed worldwide in critical infrastructure sectors including Transportation Systems, Energy, and Water and Wastewater Systems. Version 2.6.0.4R6_stable is affected by two vulnerabilities that together could allow an attacker to replace software and execute arbitrary code with root privileges.

CVE-2026-84409 is a cross-site scripting flaw (CWE-79): the device fetches update metadata over unencrypted HTTP and stores it, later reflecting attacker-controlled values into the web management interface as unsanitized HTML/script. Combined with an authenticated interface that can execute system-level commands as root, an attacker able to influence update metadata could achieve code execution in the administrative context. CVE-2026-91191 is an improper cryptographic signature verification issue (CWE-347): the boot process disables OPKG signature verification before restoring packages from a writable, unsigned feed, and the publicly distributed SDK contains the production private key trusted by both stable and beta firmware. This allows an attacker to craft signed-looking malicious packages that the device will accept and install with root privileges, even if signature checking is otherwise restored.

Lantronix has released firmware version 2.6.0.7R6 to address both issues. No public exploitation has been reported to CISA at this time. Defenders operating affected gateways should update immediately, minimize network exposure of control system devices, isolate them behind firewalls away from business networks, and use secure remote access methods such as VPNs where needed.

## Mentioned in this report

- Vulnerabilities: CVE-2026-84409, CVE-2026-91191

Source reporting: https://www.cisa.gov/news-events/ics-advisories/icsa-26-272-01

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