Vulnerability details
CVE-2026-111711
Netcore NR256CN
Netcore NR256CN through 1.5.140116 Pre-Auth Stack Overflow via Boa user_ok()
CVSS 4.0
9.3Critical
Official 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.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 9.3Critical | 4.0 | CVEProject cvelistV5 (CNA) (VulnCheck) | 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 |
| 9.8Critical | 3.1 | CVEProject cvelistV5 (CNA) (VulnCheck) | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| Netcore | NR256CN | v ≤ 1.5.140116 | CVEProject cvelistV5 (CNA) |
References and advisories
2- https://github.com/lukadqq/netcore-router-public-refs/blob/a44d562736b41c944223297e9144d2ad7fa2aff1/2026.10.15-netcore-nr256cn-basic-auth-stack-overflow.md third-party-advisory
- https://www.vulncheck.com/advisories/netcore-nr256cn-through-1.5.140116-pre-auth-stack-overflow-via-boa-user-ok third-party-advisory
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Details
- Published
- 2026-10-16
- Last updated
- 2026-10-17
- State
- Published
- Assigner (CNA)
- VulnCheck
- Kolun priority
- 25 · Low
Exploit prediction (EPSS)
0.49%
Probability of exploitation in 30 days
42.5%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- Yes
- Exploitation
- None
- Technical impact
- Total
Weaknesses (CWE)
- CWE-121Stack-based Buffer Overflow