CVE-2026-119423
OPNsense core before 26.7.8 Lockout IP Planting via WebGUI Login Username
- State
- Published
- Severity
- 6.9 Medium
- Published
- Oct 30, 2026
- Updated
- Oct 30, 2026
- Reserved
- Oct 30, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.9 Medium | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 5.3 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L | VulnCheck |
Weaknesses
- CWE-117 Improper Output Neutralization for Logs
Affected Products
| Product | Versions |
|---|---|
coreopnsense |
|
References
- https://github.com/opnsense/core/commit/14f8f7dd1d5f06522d60794a7beeac7adb9eca68patch
- https://github.com/opnsense/core/commit/2076f2c195bf9537ec220f0e5d6aff998f057410patch
- https://github.com/opnsense/core/blob/26.7.7/src/opnsense/mvc/app/library/OPNsense/Auth/AuthenticationFactory.php#L232technical-description
- https://github.com/opnsense/core/blob/26.7.7/src/opnsense/scripts/syslog/lockout_handler#L70technical-description
- GitHub Security Advisory (GHSA-2v2x-m4j7-76pv)vendor-advisory
- https://abraxaslabs.tech/research/opnsense-lockout-factory-ipthird-party-advisory
- https://github.com/opnsense/coreproduct
- VulnCheck Advisory: OPNsense core before 26.7.8 Lockout IP Planting via WebGUI Login Usernamethird-party-advisory
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