CVE-2026-42221

Published: Mag 04, 2026 Last Modified: Mag 04, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 8,1
Source: [email protected]
Attack Vector: network
Attack Complexity: high
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: high

Description

AI Translation Available

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.

306

Missing Authentication for Critical Function

Draft
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Access Control Other
Potential Impacts:
Gain Privileges Or Assume Identity Varies By Context
Applicable Platforms
Technologies: Cloud Computing, ICS/OT
Likelihood of Exploit: High
View CWE Details
https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.8
https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.8
https://github.com/0xJacky/nginx-ui/security/advisories/GHS…
https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-h27v-ph7w-m9fp