Is CVE-2026-111711 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-111711?

CVE-2026-111711 has a CVSS v3 severity of CRITICAL (9.8).

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CVE-2026-111711

Description

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.