Zyxel security advisory (AV26-603) – Update 1

Serial number: AV26-603Date: June 16, 2026Updated: September 21, 2026 On June 16, 2026, Zyxel published a security advisory to address vulnerabilities in the following products: GS1900 series switches – multiple versions and models Update 1 On September 21, 2026, Cybersecurity and Infrastructure Security Agency (CISA) added CVE-2026-7273 to their Known Exploited Vulnerabilities (KEV) Database. The Cyber Centre encourages users and administrators to review the provided web links and apply the necessary updates. Zyxel security advisory for stack-based buffer overflow vulnerability in GS1900 series switches Zyxel Advisories CISA KEV: CVE-2026-7273