pfSense is widely used as network/firewall infrastructure; this flaw enables root code execution via WebGUI and can compromise network gateways.
CVE-2026-111231
Auth bypass allows read-only WebGUI users to install config.xml and obtain root.
Is CVE-2026-111231 being exploited?
Not confirmed. CVE-2026-111231 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked.
How severe is CVE-2026-111231?
CVE-2026-111231 is rated High with a CVSS score of 8.6. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-111231?
Not known from our data. No patch reference has been recorded for CVE-2026-111231, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.
What does CVE-2026-111231 affect?
CVE-2026-111231 affects Netgate pfSense CE ≤ 2.9.0, WebGUI endpoints: services_acb.php, uploadconfig.php, diag_confbak.php, and 1 further product or version. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-111231?
Restrict WebGUI access, disable config upload/restore endpoints, rotate credentials, apply vendor patch when published
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Read-only WebGUI users can replace config.xml to achieve root-level code execution after reload/reboot.
Immediate action required
- affected<= 2.9.0
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.