CVE-2026-111711

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

Published Oct 16, 2026 CVSS 4.0 · 9.3 Critical EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Netcore
Netcore nr256cn
Vendors & Products Netcore
Netcore nr256cn
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Netcore NR256CN through 1.5.140116 Pre-Auth Stack Overflow via Boa user_ok()
Weaknesses CWE-121
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 9.3, 'vector': '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Oct 16, 2026, 9:16 PM
Reserved
Oct 16, 2026, 2:31 PM
Status
Deferred
Published
Oct 16, 2026, 6:17 PM
Modified
Oct 16, 2026, 10:17 PM