cvedb.io
CVE-2026-42221
HIGH · CVSS 8.1
EPSS exploitation probability: 0%
Published 2026-05-04T21:16:32.023 · Last modified 2026-06-17T10:47:31.917

Summary

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.

Affected products

nginxui — nginx_ui

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.