{"id":"CVE-2026-111711","state":"PUBLISHED","title":"Netcore NR256CN through 1.5.140116 Pre-Auth Stack Overflow via Boa user_ok()","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.","publishedAt":"2026-10-16T17:40:01.282Z","updatedAt":"2026-10-16T21:16:42.070Z","severity":{"score":9.3,"label":"Critical","version":"4.0","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","source":"VulnCheck"},"assigner":"VulnCheck","products":["Netcore NR256CN"],"affected":[{"vendor":"Netcore","product":"NR256CN","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"1.5.140116","versionType":"custom"}]}],"references":["https://github.com/lukadqq/netcore-router-public-refs/blob/a44d562736b41c944223297e9144d2ad7fa2aff1/2026.10.15-netcore-nr256cn-basic-auth-stack-overflow.md","https://www.vulncheck.com/advisories/netcore-nr256cn-through-1.5.140116-pre-auth-stack-overflow-via-boa-user-ok"],"weaknesses":["CWE-121"],"ingestedAt":"2026-10-29T20:10:33.477Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/111xxx/CVE-2026-111711.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-111711","state":"PUBLISHED","datePublished":"2026-10-16T17:40:01.282Z","dateUpdated":"2026-10-16T21:16:42.070Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-10-16T14:31:23.221Z"},"containers":{"cna":{"title":"Netcore NR256CN through 1.5.140116 Pre-Auth Stack Overflow via Boa user_ok()","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Netcore","product":"NR256CN","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"1.5.140116","versionType":"custom"}]}],"references":[{"url":"https://github.com/lukadqq/netcore-router-public-refs/blob/a44d562736b41c944223297e9144d2ad7fa2aff1/2026.10.15-netcore-nr256cn-basic-auth-stack-overflow.md","tags":["third-party-advisory"]},{"url":"https://www.vulncheck.com/advisories/netcore-nr256cn-through-1.5.140116-pre-auth-stack-overflow-via-boa-user-ok","name":"VulnCheck Advisory: Netcore NR256CN through 1.5.140116 Pre-Auth Stack Overflow via Boa user_ok()","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"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","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":9.3,"baseSeverity":"CRITICAL"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","baseScore":9.8,"baseSeverity":"CRITICAL"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-121","lang":"en","description":"Stack-based Buffer Overflow","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-10-16T17:40:01.282Z"},"datePublic":"2026-10-16T00:00:00.000Z","credits":[{"lang":"en","value":"Zhou Ao","type":"finder"},{"lang":"en","value":"Yin Luxing","type":"finder"},{"lang":"en","value":"Lu Fangzhou","type":"finder"},{"lang":"en","value":"Liu Xin","type":"finder"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-16T20:53:29.394899Z","id":"CVE-2026-111711","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T21:16:42.070Z"}}]}}}