CVE-2026-76070: Netis Systems NC63

Critical severity, CVSS 9.8. EPSS: 1.3% chance of exploitation in the next 30 days.

Netis NC63 firmware through V3.0.0.3327 contains a stack-based buffer overflow vulnerability that allows unauthenticated remote attackers to overwrite saved stack state by submitting an oversized Base64-encoded password to the login handler in /bin/netis.cgi. Attackers can exploit the custom Base64 decoder's lack of output length validation against the fixed-size stack buffer to achieve remote code execution with root privileges, as the Boa web server executes the CGI environment as root.

Affected products

• Netis Systems NC63: up to and including 3.0.0.3327

Published 2026-08-24. Last modified 2026-09-24.