OPNsense RCE Vulnerability (CVE-2026-44193) Exposes Firewalls
A critical remote code execution (RCE) vulnerability, tracked as CVE-2026-44193, has been identified in OPNsense, a widely used FreeBSD-based firewall and routing platform. The National Vulnerability Database (NVD) reports a CVSS score of 9.1 (CRITICAL), highlighting the severe risk this flaw poses to network perimeters.
The vulnerability stems from insufficient sanitization of user-supplied input within the opnsense.restore_config_section XMLRPC method. This allows an authenticated attacker with high privileges to execute arbitrary code remotely on affected OPNsense instances. The National Vulnerability Database indicates that all OPNsense versions prior to 26.1.7 are vulnerable.
This isn’t just a theoretical flaw; it’s a direct path to total network compromise. An attacker gaining RCE on a firewall means they control the very gateway of your network. They can pivot, exfiltrate data, or establish persistent access with ease. This vulnerability demands immediate attention from any organization running OPNsense.
What This Means For You
- If your organization uses OPNsense, you must immediately verify your version. Prioritize upgrading to version 26.1.7 or later to patch CVE-2026-44193. If immediate patching isn't feasible, review your administrative access controls for OPNsense and ensure only trusted, highly privileged users can access the XMLRPC interface, as this RCE requires high privileges.
Related ATT&CK Techniques
🛡️ Detection Rules
5 rules · 6 SIEM formats5 detection rules auto-generated for this incident, mapped to MITRE ATT&CK. Sigma YAML is free — export to any SIEM format via the Intel Bot.
Web Application Exploitation Attempt — CVE-2026-44193
title: Web Application Exploitation Attempt — CVE-2026-44193
id: scw-2026-05-13-1
status: experimental
level: high
description: |
Detects common exploitation patterns targeting web applications. Review CVE-2026-44193 advisories for specific indicators.
author: SCW Feed Engine (auto-generated)
date: 2026-05-13
references:
- https://shimiscyberworld.com/posts/nvd-CVE-2026-44193/
tags:
- attack.initial_access
- attack.t1190
logsource:
category: webserver
detection:
selection:
cs-uri-query|contains:
- '..'
- 'SELECT'
- 'UNION'
- '<script'
- 'cmd='
- '/etc/passwd'
condition: selection
falsepositives:
- Legitimate activity from CVE-2026-44193
Source: Shimi's Cyber World · License & reuse
Indicators of Compromise
| ID | Type | Indicator |
|---|---|---|
| CVE-2026-44193 | RCE | OPNsense firewall and routing platform |
| CVE-2026-44193 | RCE | OPNsense versions prior to 26.1.7 |
| CVE-2026-44193 | RCE | XMLRPC method opnsense.restore_config_section |
| CVE-2026-44193 | RCE | Failure to sanitize user supplied input |
Written by SCW Vulnerability Desk
Source & Attribution
| Source Platform | NVD |
| Channel | National Vulnerability Database |
| Published | May 14, 2026 at 01:16 UTC |
This content was AI-rewritten and enriched by Shimi's Cyber World based on the original source. All intellectual property rights remain with the original author.
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