Nginx UI: OTP secure-session step-up can be bypassed via MCP configuration tools

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

Nginx UI is a web user interface for the Nginx web server. Prior to 2.4.1, the HTTP configuration mutation routes require RequireSecureSession, but /mcp and /mcp_message require only ordinary authentication before exposing nginx_config_add and nginx_config_modify. An OTP-enabled user with a normal JWT but no valid X-Secure-Session-ID can therefore create or modify Nginx configuration and trigger reload behavior through MCP, bypassing the intended step-up control. This issue is fixed in version 2.4.1.

[ Fixes ]Fixes and patches

• github.com/0xJacky/Nginx-UI 1.9.10-0.20260703131214-23d1934099b0Fixed version · GitHub Advisories · go package github.com/0xJacky/Nginx-UI: upgrade to 1.9.10-0.20260703131214-23d1934099b0 or later (affected < 1.9.10-0.20260703131214-23d1934099b0)

[ Packages ]Affected open-source packages

• github.com/0xJacky/Nginx-UI goAffected < 1.9.10-0.20260703131214-23d1934099b0 · fixed in 1.9.10-0.20260703131214-23d1934099b0 · GHSA-vc32-4gwf-77xp

[ References ]References

• github.com/0xJacky/nginx-ui/commit/23d1934099b05b2a01589b48129dc3d3159d91c2
• github.com/0xJacky/nginx-ui/releases/tag/v2.4.1
• github.com/0xJacky/nginx-ui/security/advisories/GHSA-vc32-4gwf-77xp