CVE-2026-119423

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 (MEDIUM) Score source: NVD CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS 4.0

6.9 (MEDIUM) Score source: CNA 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/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

EPSS — exploit probability

0% (percentile: 32) as of 1 November 2026

CWE

CWE-117

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/OPNse…
• https://github.com/opnsense/core/blob/26.7.7/src/opnsense/scripts/syslog/lockou…
• 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-pla…