SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-16771

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.

HIGH 8.8EPSS 0.35%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.35%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
8.8 HIGHCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
0.35% probability · 29th percentile
CISA KEV
Not listed
Weakness
CWE-306
Source
cret@cert.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.