# CVE-2026-16771: CVE-2026-16771

> Unauthenticated attackers on the LAN can access management endpoints to read configuration data and modify device settings due to missing server-side authentication.

- **Severity:** High 8.8 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 28 Jul 2026
- **Updated:** 28 Jul 2026
- **Also known as:** GHSA-8rcq-gm95-4hqg

## What is CVE-2026-16771?

CVE-2026-16771 is a high-severity missing authorization vulnerability in AT&T Arris BGW210‑700, published on 28 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In firmware versions 2.7.7 and earlier, the Arris BGW210‑700 gateway fails to enforce any server‑side authentication on its /cgi-bin/*.ha management endpoints, relying solely on client‑side CSS/JavaScript gating that can be bypassed by any HTTP client. This allows unauthenticated attackers on the LAN to read sensitive configuration data, modify persistent device settings, or trigger backend diagnostic operations. The issue appears systemic across the CGI handler chain.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-16771?


## How do I fix CVE-2026-16771?

No fix has been published for CVE-2026-16771 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-16771 being exploited?

There is no known exploitation of CVE-2026-16771 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-16771 and fix it if it is affected.

What it is: CVE-2026-16771 is a high-severity missing authorization vulnerability in AT&T Arris BGW210‑700, published on 28 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-16771 in the wild and no public exploit code.

Affected product: AT&T Arris BGW210‑700. 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-2026-16771/ (Markdown: https://insights.sbomify.com/CVE-2026-16771/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-16771
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-16771
- OSV: https://osv.dev/vulnerability/CVE-2026-16771

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-16771/
Summaries are generated and may contain mistakes; the official description above is the record.