Description
OPNsense core before 26.7.8 contains a log injection vulnerability that allows unauthenticated attackers to plant victim IP addresses in the lockout_handler by submitting crafted WebGUI login usernames. Attackers can submit usernames like 'Invalid user <victim-ip>' repeatedly to add the victim to the sshlockout table, blocking SSH and WebGUI access and killing its pf states.
Metrics
CVSS 3.1 5.3/10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LWeakness enumeration
Affected software
Source: the vendor's advisory (CNA). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| opnsense | core | < 26.7.8 |
References
- https://abraxaslabs.tech/research/opnsense-lockout-factory-ip
- https://github.com/opnsense/core
- https://github.com/opnsense/core/blob/26.7.7/src/opnsense/mvc/app/library/OPNsense/Auth/AuthenticationFactory.php#L232
- https://github.com/opnsense/core/blob/26.7.7/src/opnsense/scripts/syslog/lockout_handler#L70
- https://github.com/opnsense/core/commit/14f8f7dd1d5f06522d60794a7beeac7adb9eca68
- https://github.com/opnsense/core/commit/2076f2c195bf9537ec220f0e5d6aff998f057410
- https://github.com/opnsense/core/security/advisories/GHSA-2v2x-m4j7-76pv
- https://www.vulncheck.com/advisories/opnsense-core-before-26.7.8-lockout-ip-planting-via-webgui-login-username
Timeline
- Published
- Oct 30, 2026
- Last modified
- Nov 4, 2026
- NVD status
- Awaiting Analysis