{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-42221", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-04-25T05:04:37.029Z", "datePublished": "2026-05-04T20:09:37.308Z", "dateUpdated": "2026-05-04T20:09:37.308Z"}, "containers": {"cna": {"title": "nginx-ui: Unauthenticated First-Run Installer Allows Remote Initial Admin Claim", "problemTypes": [{"descriptions": [{"cweId": "CWE-306", "lang": "en", "description": "CWE-306: Missing Authentication for Critical Function", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-h27v-ph7w-m9fp", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-h27v-ph7w-m9fp"}, {"name": "https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.8", "tags": ["x_refsource_MISC"], "url": "https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.8"}], "affected": [{"vendor": "0xJacky", "product": "nginx-ui", "versions": [{"version": ">= 2.0.0, < 2.3.8", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-05-04T20:09:37.308Z"}, "descriptions": [{"lang": "en", "value": "Nginx UI is a web user interface for the Nginx web server. From version 2.0.0 to before version 2.3.8, an unauthenticated network attacker can claim the initial administrator account on a fresh nginx-ui instance during the first-run setup window. The public /api/install endpoint is reachable without authentication, and the request-encryption flow only protects payload confidentiality in transit; it does not authenticate who is allowed to perform installation. A remote attacker who reaches the service before the legitimate operator can set the admin email, username, and password, causing permanent initial-instance takeover. This issue has been patched in version 2.3.8."}], "source": {"advisory": "GHSA-h27v-ph7w-m9fp", "discovery": "UNKNOWN"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "Nginx UI is a web user interface for the Nginx web server. From version 2.0.0 to before version 2.3.8, an unauthenticated network attacker can claim the initial administrator account on a fresh nginx-ui instance during the first-run setup window. The public /api/install endpoint is reachable without authentication, and the request-encryption flow only protects payload confidentiality in transit; it does not authenticate who is allowed to perform installation. A remote attacker who reaches the service before the legitimate operator can set the admin email, username, and password, causing permanent initial-instance takeover. This issue has been patched in version 2.3.8."}], "id": "CVE-2026-42221", "lastModified": "2026-05-04T21:16:32.023", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 5.9, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-05-04T21:16:32.023", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.8"}, {"source": "security-advisories@github.com", "url": "https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-h27v-ph7w-m9fp"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-306"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[2.0.0,2.3.8)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "nginx-ui", "source": "cna", "vendor": "0xJacky"}, "product": "nginx-ui", "vendor": "0xjacky"}], "created": "2026-05-04T21:30:08.835637+00:00", "updated": "2026-05-04T22:00:11.475290+00:00", "vendors": ["0xjacky", "0xjacky$PRODUCT$nginx-ui"]}