CVE-2026-111231
HIGH 8.6Netgate pfSense CE through 2.9.0 contains an authorization bypass vulnerability that allows read-only WebGUI users to replace config.xml because config_restore() and config_install() ignore the 'User - Config: Deny Config Write' privilege. Attackers holding page privileges for services_acb.php, uploadconfig.php, diag_confbak.php, or diag_backup.php can install a chosen config.xml to gain root-level code execution after reload or reboot.
Severe if exploited (CVSS 8.6), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.8%chance of exploitation in 30 days · 58th percentile
Impact if exploited
8.6CVSS 4.0 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires an admin / high-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
- ✓Requirements: No special attack requirements
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
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Data snapshot:
Weakness (CWE)
- CWE-863: Incorrect Authorization
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
References and research data (JSON)
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Pfsense | Pfsense | ≤ 2.9.0 |
All CVSS metrics
- HIGH 8.6 v4.0 · CNA Primary
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - HIGH 7.2 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - HIGH 8.6 v4.0 · NVD Secondary
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - HIGH 7.2 v3.1 · NVD Primary
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
References
Exploit-tagged references (not proof of a PoC)
- https://github.com/abraxas/pfsense-config-readonly-restore CVE record · VulnCheck · Updated 2026-10-15T18:46:31.461Z
NVD · CVE-2026-111231 · Updated 2026-10-19T20:42:14.583
Advisories
- https://www.vulncheck.com/advisories/netgate-pfsense-ce-through-2.9.0-authorization-bypass-via-config-restore-and-config-install CVE record · VulnCheck · Updated 2026-10-15T18:46:31.461Z
NVD · CVE-2026-111231 · Updated 2026-10-19T20:42:14.583 - https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-102343 EUVD · EUVD-2026-102343
Technical & other
- https://abraxaslabs.tech/research/pfsense-ce-leftovers CVE record · VulnCheck · Updated 2026-10-15T18:46:31.461Z
NVD · CVE-2026-111231 · Updated 2026-10-19T20:42:14.583 - https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/etc/inc/config.lib.inc#L743-L798 CVE record · VulnCheck · Updated 2026-10-15T18:46:31.461Z
NVD · CVE-2026-111231 · Updated 2026-10-19T20:42:14.583 - https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/etc/inc/config.lib.inc#L588-L597 CVE record · VulnCheck · Updated 2026-10-15T18:46:31.461Z
NVD · CVE-2026-111231 · Updated 2026-10-19T20:42:14.583