CVE-2026-42222: Nginx-UI: Unauthenticated first-boot instance claim via POST /api/install allows remote bootstrap takeover

Severity: Critical

CVSS Score: 8.1

Nginx UI is a web user interface for the Nginx web server. In version 2.3.5, an unauthenticated bootstrap takeover exists in nginx-ui during the initial installation window exposed by POST /api/install. At time of publication no public patches are available.