CVE-2026-42221

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Source
https://cve.org/CVERecord?id=CVE-2026-42221
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42221.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-42221
Aliases
Published
2026-05-04T20:09:37.308Z
Modified
2026-07-08T08:13:13.806012286Z
Severity
  • 8.1 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
nginx-ui: Unauthenticated First-Run Installer Allows Remote Initial Admin Claim
Details

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.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-306"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42221.json"
}
References

Affected packages

Git / github.com/0xjacky/nginx-ui

Affected ranges

Type
GIT
Repo
https://github.com/0xjacky/nginx-ui
Events
Introduced
daee3ac7ade1162805b3af07807e2f4dc2affaf5
Fixed
7864e378f5cf8013c4df38c15e57480f5c2db1d7
Database specific 
{
    "extracted_events": [
        {
            "introduced": "2.0.0"
        },
        {
            "fixed": "2.3.8"
        }
    ],
    "cpe": "cpe:2.3:a:nginxui:nginx_ui:*:*:*:*:*:*:*:*",
    "source": [
        "AFFECTED_FIELD",
        "CPE_RANGE",
        "REFERENCES"
    ]
}

Affected versions

v2.*
v2.0.0
v2.0.1
v2.0.2
v2.1.0
v2.1.0-beta.1
v2.1.0-patch.1
v2.1.0-rc.1
v2.1.0-rc.2
v2.1.0-rc.3
v2.1.1
v2.1.10
v2.1.11
v2.1.12
v2.1.13
v2.1.14
v2.1.15
v2.1.16
v2.1.17
v2.1.2
v2.1.3
v2.1.4
v2.1.4-patch.1
v2.1.5
v2.1.6
v2.1.7
v2.1.8
v2.1.9
v2.2.0
v2.2.0-patch.1
v2.2.1
v2.3.0
v2.3.1
v2.3.2
v2.3.3
v2.3.4
v2.3.5
v2.3.6
v2.3.7

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42221.json"