CVE-2026-111711: Netcore NR256CN

Critical severity, CVSS 9.8. EPSS: 0.5% chance of exploitation in the next 30 days.

Netcore NR256CN through 1.5.140116 contains a pre-authentication stack overflow vulnerability in the Boa web server's user_ok() function, which copies Basic-auth usernames with unbounded strcpy() calls into 64-byte stack buffers. Unauthenticated attackers can send a username longer than 63 bytes to any protected /router/*.cgi route to crash the main Boa process or potentially execute code.

Affected products

• Netcore NR256CN: up to and including 1.5.140116

Published 2026-10-16. Last modified 2026-10-16.