CVEvulnerability

CVE-2026-42221

9.8 CRITICAL Published 2026-05-04 Modified 2026-10-26 Official page ↗
Status
Analyzed
Published
2026-05-04
Last modified
2026-10-26
Assigner
[email protected]
CVSS 3.1 ([email protected])
8.1 HIGH — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 3.1 ([email protected])
9.8 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weaknesses
CWE-306

Description

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 configurations

• nginxui nginx ui (>= 2.0.0 < 2.3.8)

Related

Weakness · CWE (1)

  • CWE-306 Missing Authentication for Critical Functionality weakness

References