CVE-2026-57154: opnsense core · Injection
Affects opnsense coreSource CVE Database V5
Not known to be exploited · CVSS 8.1 High : upgrade to 26.1.11 soon.
Data as of 3 Nov 2026, 18:43 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 8.1 |
|---|
- Patch
- Available – fixed in 26.1.11
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 3 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.
What to do
Upgrade opnsense core to 26.1.11.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| opnsensecore | Affected
| Fixed in
|
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.