Pre-Authentication Stack Overflow in Netcore NR256CN by Netcore
CVE-2026-111711

9.3CRITICAL

Key Information:

Vendor

Netcore

Status
Nr256cn
Vendor
CVE Published:
16 October 2026

What is CVE-2026-111711?

The Netcore NR256CN, up to version 1.5.140116, is susceptible to a pre-authentication stack overflow vulnerability in the Boa web server's user_ok() function. This flaw allows unauthenticated attackers to exploit the Basic-auth mechanism by supplying a username longer than 63 bytes, leading to potential crashes of the Boa process or even arbitrary code execution. Such vulnerabilities pose significant risk when attackers can manipulate server processes through unhandled input parameters.

Affected Version(s)

NR256CN 0 <= 1.5.140116

References

https://github.com/lukadqq/netcore-router-public-refs/blo...
third-party-advisory
https://www.vulncheck.com/advisories/netcore-nr256cn-thro...
third-party-advisory

CVSS V4

Score:
9.3
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Zhou Ao
Yin Luxing
Lu Fangzhou
Liu Xin
.