CVE-2026-76071

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 supplying an oversized destHost parameter to the ipFilterList=mod action in netis.cgi. Attackers can exploit widthless sscanf conversions that copy user-supplied input into fixed-size stack buffers before authentication is verified, achieving remote code execution as root due to the Boa web server executing the CGI environment with root privileges.

CVSS 4.0

9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

1.4% chance of exploitation in the next 30 days; higher than 72% of CVEs (scores of 2026-10-25)

CWE

CWE-121

Published

2026-08-24

Modified

2026-10-12

Record from

the NVD, synced 2026-10-19

References

• https://github.com/ozcanpng/CVE-2026-76071
• https://ozcanpng.dev/blog/cve-2026-76071-netis-nc63-ipfilter-stack-buffer-overflow/
• https://www.netis-systems.com/products/NC63.html
• https://www.vulncheck.com/advisories/netis-nc63-stack-buffer-overflow-via-desthost-parameter

Check your stackJSON