CVE-2026-44194

Critical

Description

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.

SeverityCritical

CVSS9.1

Exploit probability—

ProductOpnsense

PublishedMay 13, 2026

First seenMay 13, 2026

Weakness typeCWE-78OS command injection

How to fix

Update

opnsense opnsense26.1.8 or later

Affected products

Product	Affected versions	Fixed in
opnsense opnsense	v < 26.1.8	26.1.8

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