CVE-2026-7273 — Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability

Impacted if

Zyxel GS1900 Series Switches

CISA Known Exploited Vulnerabilities

Added on 2026-09-21, federal remediation due 2026-09-24. Zyxel GS1900 series switches contain a stack-based buffer overflow vulnerability in the CGI program which could allow a LAN-based, unauthenticated attacker to exploit the flaw and potentially execute OS commands via a crafted HTTP request.

Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

First seen by AX-NEWS 22 Sep 2026, 05:31 UTC · latest story 22 Sep 2026, 05:31 UTC. Severity: NVD, or the CVE record while the NVD has not scored it. This product uses data from the NVD API but is not endorsed or certified by the NVD.