# CVE-2026-119425: OPNsense 26.1.6 through 26.7.7 Captive Portal Session Takeover via Forged ARP


- **Severity:** Medium 5.3 (`CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 30 Oct 2026
- **Updated:** 30 Oct 2026
- **Also known as:** GHSA-48x9-g485-9vgw, GHSA-864r-q4j5-5mjq

## What is CVE-2026-119425?

CVE-2026-119425 is a medium-severity vulnerability in opnsense core, published on 30 Oct 2026. 

### Official description

OPNsense core 26.1.6 through 26.7.7 contains an authentication bypass vulnerability in the captive portal roaming feature that lets unauthenticated attackers hijack authorized client sessions by spoofing unauthenticated MAC-to-IP observations. Attackers on the same Layer-2 segment can send forged gratuitous ARP replies binding their IP to a victim's MAC, gaining portal access with traffic attributed to the victim.

Weakness: CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2026-119425?


## How do I fix CVE-2026-119425?

No fix has been published for CVE-2026-119425 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-119425 being exploited?

There is no known exploitation of CVE-2026-119425 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-119425 and fix it if it is affected.

What it is: CVE-2026-119425 is a medium-severity vulnerability in opnsense core, published on 30 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-119425 in the wild and no public exploit code.

Affected product: opnsense core. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-119425/ (Markdown: https://insights.sbomify.com/CVE-2026-119425/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-119425
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-119425
- OSV: https://osv.dev/vulnerability/CVE-2026-119425

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-119425/
Summaries are generated and may contain mistakes; the official description above is the record.