CVE-2026-119423

CVSS 6.9 (medium) · published 2026-10-30

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.

Weakness: CWE-117

Source: NVD CVE-2026-119423

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

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