OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.8, unsanitized user input is passed to the DHCP configuration of the configured interface, which is processed by a shell script, allowing remote code execution as root on the underlying operating system. This vulnerability is fixed in 26.1.8.
https://github.com/opnsense/core/security/advisories/GHSA-5rx3-w735-74wm