{"id":"CVE-2026-111711","title":"Netcore NR256CN through 1.5.140116 Pre-Auth Stack Overflow via Boa user_ok()","summary":"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. Unauthe…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-121"],"vendor":"Netcore","product":"NR256CN","affected":["NR256CN <= 1.5.140116"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T20:53:29.394899Z"},"published":"2026-10-16","updated":"2026-10-16","sourceUpdated":"2026-10-16T21:16:42.070Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-111711","references":[{"url":"https://github.com/lukadqq/netcore-router-public-refs/blob/a44d562736b41c944223297e9144d2ad7fa2aff1/2026.10.15-netcore-nr256cn-basic-auth-stack-overflow.md"},{"url":"https://www.vulncheck.com/advisories/netcore-nr256cn-through-1.5.140116-pre-auth-stack-overflow-via-boa-user-ok","label":"VulnCheck Advisory: Netcore NR256CN through 1.5.140116 Pre-Auth Stack Overflow via Boa user_ok()"}],"tags":["cve.org"],"ingestedAt":"2026-10-16T18:43:08.639Z","slug":"CVE-2026-111711","body":"## Overview\n\nNetcore 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.\n\n## Affected\n\n- `NR256CN <= 1.5.140116`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}