CVE-2026-7273 · Zyxel GS1900 Series Switches: Zyxel GS1900 Series Switches Stack-Based Buffer Overflow Vulnerability
[CISA KEV actively exploited] Vendor: Zyxel | Product: GS1900 Series Switches | 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. | Due date: 2026-09-24 | Ransomware use: Unknown | Added: 2026-09-21 CVEs: CVE-2026-7273. CISA KEV/exploitation signal detected. Vendors: Zyxel. DORA relevance: medium.