GPL Odorizers GPL750 Vulnerability Allows Modbus Tampering
🔐 A vulnerability in GPL Odorizers GPL750 controllers (CVE-2026-4436) permits a low-privileged remote attacker to send unauthenticated Modbus packets that alter register values used by the odorant injection logic, potentially causing excessive or insufficient odorant dosing in gas lines. Affected XL4/XL4 Prime/XL7/XL7 Prime firmware ranges are documented and the issue is rated CVSS 3.1 8.6 (High). Vendors provide firmware updates and installation guidance; apply updates, isolate controllers on control networks, and follow ICS security best practices.
