Nginx UI: nginx config directive denylist (ValidateConfigFile) is bypassable via same-line ";" separation → authenticated directive injection (RCE on the official image)

Summary

Nginx UI is a web user interface for the Nginx web server. Prior to 2.4.1, config.ValidateConfigDirectives splits configuration by newline and checks only the first directive token on each line even though Nginx permits multiple semicolon-separated directives on one line. An authenticated caller can place a benign directive first and a restricted load_module, js_import, perl, or user root directive later on the same line, or can use an unrestricted include directive to load restricted content. These mechanisms bypass validation on REST, nginx_config_modify, site, and stream write paths; when an executable module is available, the injected configuration can execute code in the Nginx worker context. This issue is fixed in version 2.4.1.

Timeline

1. Oct 12, 2026, 9:05 PM UTCCVE published
2. Oct 13, 2026, 2:48 PM UTCCISA SSVC assessment

   Exploitation: poc · Automatable: no · Technical impact: total

3. Oct 13, 2026, 2:48 PM UTCRecord last updated

Affected versions

• 0xJacky nginx-ui

  fixed in 2.4.1

• github.com/0xJacky/Nginx-UIGo

  fixed in 1.9.10-0.20260703131214-23d1934099b0

References 3