CVE-2026-111711: critical vulnerability in Netcore NR256CN
Netcore NR256CN through 1.5.140116 Pre-Auth Stack Overflow via Boa user_ok()
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.3epss 0.5%
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Affected products
Netcore · NR256CNRelated CVEs — Netcore NR256CN
In the same product, most dangerous first.
CVE-2026-112016MEDIUMNetcore NR256CN through 1.5.140116 Unauthenticated Write to Fixed Boa Staging FilesEPSS 0.3%CVE-2026-111710HIGHNetcore NR256CN through 1.5.140116 Boa Web Server NULL Pointer Dereference DoSEPSS 0.3%CVE-2026-111712MEDIUMNetcore NR256CN through 1.5.140116 Authentication Bypass via CGI Path PrefixEPSS 0.2%