CVE-2026-44194: CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in opnsense core
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.
AI Analysis
Technical Summary
OPNsense core, a FreeBSD-based firewall and routing platform, contains an OS command injection vulnerability (CWE-78) in versions before 26.1.8. An authenticated user with user-management privileges can exploit this by injecting shell commands formatted as compliant email addresses in the local user synchronization flow (core/src/opnsense/scripts/auth/sync_user.php). This leads to remote code execution with root privileges. The vulnerability has a CVSS 3.1 score of 9.1, indicating critical severity. The issue is resolved in OPNsense version 26.1.8.
Potential Impact
Successful exploitation allows an authenticated user with user-management privileges to execute arbitrary commands as root on the underlying operating system, resulting in full system compromise. Confidentiality, integrity, and availability of the affected system are severely impacted.
Mitigation Recommendations
This vulnerability is fixed in OPNsense core version 26.1.8. Users should upgrade to version 26.1.8 or later to remediate this issue. No other official remediation or temporary fixes are documented. Patch status is confirmed by the vendor advisory indicating the fix is included in 26.1.8.
CVE-2026-44194: CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in opnsense core
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.
CVSS v3.1
Score 9.1critical
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
OPNsense core, a FreeBSD-based firewall and routing platform, contains an OS command injection vulnerability (CWE-78) in versions before 26.1.8. An authenticated user with user-management privileges can exploit this by injecting shell commands formatted as compliant email addresses in the local user synchronization flow (core/src/opnsense/scripts/auth/sync_user.php). This leads to remote code execution with root privileges. The vulnerability has a CVSS 3.1 score of 9.1, indicating critical severity. The issue is resolved in OPNsense version 26.1.8.
Potential Impact
Successful exploitation allows an authenticated user with user-management privileges to execute arbitrary commands as root on the underlying operating system, resulting in full system compromise. Confidentiality, integrity, and availability of the affected system are severely impacted.
Mitigation Recommendations
This vulnerability is fixed in OPNsense core version 26.1.8. Users should upgrade to version 26.1.8 or later to remediate this issue. No other official remediation or temporary fixes are documented. Patch status is confirmed by the vendor advisory indicating the fix is included in 26.1.8.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-05T15:13:47.570Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a052a70cbff5d86103e0d7c
Added to database: 05/14/2026, 01:50:40 UTC
Last enriched: 05/21/2026, 11:55:20 UTC
Last updated: 07/31/2026, 19:22:59 UTC
Views: 122
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