8.8
HIGH CVSS 3.1
CVE-2026-16771
CVE-2026-16771
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.

INFO

Published Date :

July 28, 2026, 7:17 p.m.

Last Modified :

July 28, 2026, 8:17 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-16771 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH 134c704f-9b21-4f2e-91b3-4a467353bcc0
Solution
Update device firmware to patch authentication bypass on management endpoints.
  • Update the device firmware.
  • Apply vendor patches for the gateway.
  • Enforce server-side authentication.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-16771.

URL Resource
https://kb.cert.org/vuls/id/141367
https://www.kb.cert.org/vuls/id/141367
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-16771 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-16771 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-16771 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 28, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-306
    Added SSVC {'id': 'CVE-2026-16771', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-28T18:58:28.079223Z'}
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Jul. 28, 2026

    Action Type Old Value New Value
    Added Reference https://www.kb.cert.org/vuls/id/141367
  • New CVE Received by [email protected]

    Jul. 28, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'AT&T', 'product': 'Arris BGW210‑700', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'custom', 'lessThanOrEqual': '2.7.7'}]}]
    Added 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.
    Added Reference https://kb.cert.org/vuls/id/141367
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.