OS Command Injection in OPNsense - CVE-2026-44194
Published: May 12, 2026
Vulnerability identifier: #VU131108
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-44194
CWE-ID: CWE-78
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Deciso
Affected software:
OPNsense
OPNsense
Detailed vulnerability description
The vulnerability allows a remote user to execute arbitrary system commands as root.
The vulnerability exists due to improper neutralization of special elements used in an os command in core/src/opnsense/scripts/auth/sync_user.php when synchronizing local user changes. A remote privileged user can supply a crafted email address as a username to execute arbitrary system commands as root.
The issue occurs because quoted email local-parts can contain shell metacharacters that pass username validation and are then interpreted by the shell.
How to mitigate CVE-2026-44194
Install security update from vendor's website.