Authentication bypass using an alternate path or channel in nginx-ui - #VU142584
Published: August 14, 2026
Vulnerability identifier: #VU142584
CSH Severity: Medium
CVSS v4: 7.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-288
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to bypass the secure-session step-up requirement and modify Nginx configuration.
The vulnerability exists due to authentication bypass using an alternate path or channel in the /mcp and /mcp_message MCP endpoints when handling configuration mutation requests. A remote user can use the nginx_config_add or nginx_config_modify tools through the MCP interface to bypass the secure-session step-up requirement and modify Nginx configuration.
Only OTP-enabled accounts are affected, and exploitation requires the MCP feature to be enabled.
Affected software
nginx-ui
Remediation
Install security update from vendor's website.
nginx-ui - update to 2.4.1