CVE-2026-44194: Opnsense

Critical severity, CVSS 9.1. EPSS: 0.8% chance of exploitation in the next 30 days.

OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.8, an authenticated Remote Code Execution (RCE) vulnerability in the OPNsense core allows a user with user-management privileges to execute arbitrary system commands as root. An attacker can bypass input validation by formatting their malicious payload as a compliant email address, allowing shell commands to reach the underlying operating system. The flaw exists in the local user synchronization flow, within core/src/opnsense/scripts/auth/sync_user.php. This vulnerability is fixed in 26.1.8.

Affected products

• Opnsense Opnsense: before 26.1.8 (fixed in 26.1.8)

Published 2026-05-13. Last modified 2026-06-17.