Netgate pfSense CE: OS command injection via CARP VHID
Summary
Netgate pfSense CE through 2.9.0 contains an OS command injection in the handling of CARP Virtual IP settings. An authenticated user with Virtual IP edit privileges can store a crafted CARP VHID value that is passed unescaped to shell commands, which run as root. Successful exploitation gives an attacker full control over the firewall, its traffic and the connected networks. No vendor fix or advisory for this CVE has been published yet.
Affected
- Netgate pfSense CE up to and including 2.9.0 (according to the CNA data)
- Default configurations are listed as unaffected in the CNA data
- Plus editions are not named in the CVE data
Fixed in
Unknown.
Workaround
- Restrict access to the pfSense web GUI to management networks or VPN only
- Limit Virtual IP edit and apply rights to a minimal set of administrators
- Review existing Virtual IP and CARP configurations for unexpected VHID values
- No vendor mitigation has been published
Exploitation
- A public proof of concept exists (GitHub, by the researcher)
- CISA SSVC assessment: exploitation status PoC, not automatable
- EPSS about 7 percent (Vulners)
- No evidence of active exploitation found; not verified against the CISA KEV catalog
Our recommendation
- Check whether pfSense CE is in use and whether the web GUI is reachable from the internet
- Restrict the web GUI to trusted management networks or VPN
- Reduce the number of accounts with Virtual IP edit and apply rights and audit them
- Review Virtual IP and CARP settings for unexpected values
- Monitor the Netgate advisories and the NVD entry and apply the fix as soon as it is published
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Abraxas Labs research: pfSense CARP VHID abraxaslabs.tech
- VulnCheck advisory: Netgate pfSense CE OS command injection via CARP VHID www.vulncheck.com
- Vulners CVE record CVE-2026-111217 vulners.com
- Vulners CNA record CVE-2026-111217 vulners.com
- pfSense source: CARP status grep (pfsense-utils.inc) github.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 08:01.
Original description (NVD)
Netgate pfSense CE through 2.9.0 contains an OS command injection vulnerability that allows authenticated users with Virtual IP edit privileges to execute commands as root by storing an unvalidated CARP VHID. Attackers can supply a VHID containing shell metacharacters that executes via interface_ipalias_configure() ifconfig calls or get_carp_interface_status() when CARP status is rendered.
NVD references (7)
- https://abraxaslabs.tech/research/pfsense-carp-vhid
- https://abraxaslabs.tech/research/pfsense-ce-leftovers
- https://github.com/abraxas/pfsense-carp-vhid
- https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/etc/inc/interfaces.inc#L…
- https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/etc/inc/pfsense-utils.in…
- https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/usr/local/pfSense/includ…
- https://www.vulncheck.com/advisories/netgate-pfsense-ce-through-2.9.0-os-command-injection-via-carp-vhid
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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