CVE-2026-119423

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.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
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

Configurations

No configuration.

History

30 Oct 2026, 12:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-30 12:16

Updated : 2026-10-30 19:14

NVD link : CVE-2026-119423

Mitre link : CVE-2026-119423

CVE.ORG link : CVE-2026-119423

JSON object : View

Products Affected

No product.

CWE

CWE-117

Improper Output Neutralization for Logs

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