High · CVSS 8.1CVE-2026-57154

OPNsense: Configuration line injection via multiple GUI text fieldsCVE-2026-57154

Answer in brief

CVE-2026-57154 records a High severity (CVSS 8.1) vulnerability in OPNsense: Configuration line injection via multiple GUI text fields. The current sources do not mark it as known exploited. The current feed maps opnsense/core (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Nov 3, 2026Updated Nov 3, 2026Source checked Nov 3, 2026First seen by HOL Nov 3, 2026Material review Nov 3, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.1
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 8.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps opnsense/core (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
opnsense/coregeneric	<26.1.11	26.1.11

Recommended response

Check inventory. Check lockfiles and deployed manifests for opnsense/core.
Review the reported fix. Update opnsense/core to 26.1.11 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Nov 3, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Nov 3, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Nov 3, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.