by Kastro
Paper/Archive/CVE-2026-111711

CVE-2026-111711

Netcore NR256CN — Netcore NR256CN through 1.5.140116 Pre-Auth Stack Overflow via Boa user_ok()

EPSS 0.5%CVSS 9.8
critical.is priorityof 100
38
CVSS 9.8 (CNA)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 42.2.422 × 208.4No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
NR256CN≤ 1.5.140116–CNA

Scores by source

VulnCheck (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
VulnCheck (CNA)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
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

writeupgithub.com/lukadqq/netcore-router-public-refs/blob/a44d562736b41c944223297e9144d2ad7fa2aff1/2026.10.15-netcore-nr256cn-basic-auth-stack-overflow.mdwriteupvulncheck.com/advisories/netcore-nr256cn-through-1.5.140116-pre-auth-stack-overflow-via-boa-user-ok