CVE-2026-111711
Critical
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.
SeverityCritical
CVSS9.8
Exploit probability—
ProductNR256CN
PublishedOct 16, 2026
First seenOct 16, 2026
Weakness typeCWE-121CWE-121
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Netcore NR256CN | v ≤ 1.5.140116 | — |
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