OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.11 and 26.4.1p1, authenticated Web UI or API users with delegated access to affected settings can submit CR or LF characters in fields expected to contain one line, causing generated privileged service configuration files to contain additional attacker-controlled directives or policy lines. The confirmed Dnsmasq path includes dhcp_boot.filename, dhcp_boot.servername, dhcp_boot.address, and dhcp_options.value, which are rendered into /usr/local/etc/dnsmasq.conf; access through page-services-dnsforwarder covers api/dnsmasq/*. Related affected fields span OpenVPN, DHCPv6, Unbound, IPsec, NTP, PPP or MPD, Monit, firewall, sudo, WebGUI, and System General configuration. Applying or restarting the affected service can alter behavior beyond the delegated setting, create service-side files, cross RBAC boundaries, or cause denial of service. Line injection through Monit mail password and adjacent Monit text fields into /usr/local/etc/monitrc demonstrated root command execution. Arbitrary shell command execution was not confirmed for the Dnsmasq path. This issue is fixed in versions 26.1.11 and 26.4.1p1.
Advisories
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Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Tue, 03 Nov 2026 20:00:00 +0000
| Type | Values Removed | Values Added |
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| First Time appeared |
Opnsense
Opnsense core |
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| Vendors & Products |
Opnsense
Opnsense core |
Tue, 03 Nov 2026 18:30:00 +0000
| Type | Values Removed | Values Added |
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| Description | OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.11 and 26.4.1p1, authenticated Web UI or API users with delegated access to affected settings can submit CR or LF characters in fields expected to contain one line, causing generated privileged service configuration files to contain additional attacker-controlled directives or policy lines. The confirmed Dnsmasq path includes dhcp_boot.filename, dhcp_boot.servername, dhcp_boot.address, and dhcp_options.value, which are rendered into /usr/local/etc/dnsmasq.conf; access through page-services-dnsforwarder covers api/dnsmasq/*. Related affected fields span OpenVPN, DHCPv6, Unbound, IPsec, NTP, PPP or MPD, Monit, firewall, sudo, WebGUI, and System General configuration. Applying or restarting the affected service can alter behavior beyond the delegated setting, create service-side files, cross RBAC boundaries, or cause denial of service. Line injection through Monit mail password and adjacent Monit text fields into /usr/local/etc/monitrc demonstrated root command execution. Arbitrary shell command execution was not confirmed for the Dnsmasq path. This issue is fixed in versions 26.1.11 and 26.4.1p1. | |
| Title | OPNsense: Configuration line injection via multiple GUI text fields | |
| Weaknesses | CWE-74 CWE-93 |
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| References |
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| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-11-03T18:10:28.787Z
Reserved: 2026-06-24T01:45:48.698Z
Link: CVE-2026-57154
No data.
Status : Received
Published: 2026-11-03T19:18:06.513
Modified: 2026-11-03T19:18:06.513
Link: CVE-2026-57154
No data.
OpenCVE Enrichment
Updated: 2026-11-03T19:45:14Z