CVE Catalog

CVE-2026-57154

HighCVSS 8.1
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.46%

40th percentile - higher than 40% of all known CVEs

Summary

In OPNsense 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. This spans Dnsmasq, OpenVPN, DHCPv6, Unbound, IPsec, NTP, PPP/MPD, Monit, firewall, sudo, WebGUI, and System General configuration; line injection through the Monit mail password into /usr/local/etc/monitrc demonstrated root command execution.

Risk Assessment

Potential RBAC boundary crossing, altered service behavior, service-side file creation, and denial of service, and in the Monit case root command execution. Requires authenticated access with delegated privileges.

Recommendation

Update OPNsense to version 26.1.11 or 26.4.1p1 or later and review delegated permissions and generated configuration files for injected lines.

Other vulnerabilities in OPNsense

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS