CVE-2026-7273
Stack-Based Buffer Overflow in Zyxel GS1900 Series Switches. CISA confirmed attackers exploit it and added it to its Known Exploited Vulnerabilities catalog on 21 September 2026.
- Product
- Zyxel GS1900 Series Switches
- Added to CISA's catalog
- Federal fix-by date
- Ransomware
- No known use in ransomware campaigns
- Sources
- CISA’s catalog, NVD entry
CISA’s description.
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.
Every flaw CISA confirmed exploited in the last 30 days is on the exploit watch. This is not security advice. Check the vendor’s advisory before acting. From CISA’s catalog of 4 November 2026.