Vulnerabilities

Nginx UI is a web user interface for the Nginx web server. In 2.3.4 and earlier, an authenticated user can perform Server-Side Request Forgery (SSRF) by creating a cluster node pointing to an arbitrary internal URL and then sending API requests with the X-Node-ID header. The Proxy middleware forwards these requests to the attacker-specified internal address, bypassing network segmentation and enabling access to services bound to localhost or internal networks.

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.

Nginx UI is a web user interface for the Nginx web server. Prior to version 2.3.4, a user who was disabled by an administrator can use previously issued API tokens for up to the token lifetime. In practice, disabling a compromised account does not actually terminate that user’s access, so an attacker who already stole a JWT can continue reading and modifying protected resources after the account is marked disabled. Since tokens can be used to create new accounts, it is possible the disabled user to maintain the privilege. Version 2.3.4 patches the issue.

Nginx UI versions 2.3.5 and prior ship a Model Context Protocol (MCP) integration exposed via two HTTP endpoints, /mcp and /mcp_message; while /mcp requires authentication, /mcp_message enforces only IP whitelisting, and the default whitelist is empty, which the middleware treats as allow-all, so the endpoint accepts requests with no authentication (CWE-306, missing authentication for a critical function). An attacker with network reachability to /mcp_message can invoke all MCP tools unauthenticated, including restarting nginx, creating, modifying, or deleting nginx configuration files, and triggering automatic config reloads. This yields complete takeover of the nginx service on the affected host, with critical-severity impact across confidentiality, integrity, and availability (CVSS 3.1: 9.8). All Nginx UI deployments running 2.3.5 or earlier are affected, especially those where the MCP endpoints are reachable from untrusted networks. News reports indicate the flaw is being actively exploited in the wild; it is not yet in CISA KEV, EPSS is high at 36.3% (98th percentile), and no patched release was available at publication.

Do: No fixed release was available at publication — monitor the upstream advisory (GHSA-h6c2-x2m2-mwhf) and the Nginx UI project and upgrade as soon as a patched version ships. Until then, restrict exposure of /mcp_message by setting a non-empty IP whitelist, firewalling the MCP endpoints to trusted management addresses or localhost/VPN only, or disabling the MCP integration. Review access logs for unauthenticated requests to /mcp_message and check for unexpected nginx config changes or restarts, which would indicate exploitation.

Nginx UI (a third-party web administration interface for the Nginx web server) prior to version 2.3.3 exposes its /api/backup endpoint without any authentication (CWE-306) and returns the backup encryption keys in the X-Backup-Security response header (CWE-311). Any unauthenticated attacker who can reach the endpoint over the network can send a single request and receive a full system backup containing user credentials, session tokens, SSL/TLS private keys, and Nginx configurations, then decrypt it immediately using the key leaked in the same response. This effectively hands the attacker the secrets needed to impersonate administrators, decrypt protected data, and potentially take over the underlying Nginx server. All deployments running Nginx UI before 2.3.3 are affected, with the greatest risk on instances where the API is reachable from the internet or from untrusted networks. A public security advisory has been published; the flaw is not yet in CISA KEV, but EPSS assigns a 22.2% probability of exploitation within 30 days (98th percentile), and a separate Nginx UI flaw (CVE-2026-33032) is reported as actively exploited, indicating attackers are targeting this product.

Do: Upgrade Nginx UI to version 2.3.3 or later immediately. If upgrading is not possible, restrict network access to the /api/backup endpoint (firewall rules, allowlists, or placing the interface behind authentication or on localhost only), and check access logs for unauthenticated requests to /api/backup or downloads using the X-Backup-Security header. If exposure is suspected, rotate all secrets contained in backups, including admin passwords, SSL/TLS private keys, and active session tokens.

Nginx UI, a third-party web management interface for the Nginx web server, fails to validate the input supplied when configuring logrotate, passing it directly to exec.Command and enabling arbitrary command execution (CWE-20, improper input validation). An attacker who can reach an affected Nginx UI instance over the network can trigger the flaw via the logrotate configuration feature, with no privileges or user interaction required per the CVSS 4.0 scoring (AV:N/AC:L/PR:N/UI:N). Successful exploitation grants full command execution on the host running Nginx UI, with high impact on confidentiality, integrity, and availability (CVSS 4.0 score 8.9, High). All Nginx UI deployments running versions prior to 2.0.0-beta.36 are affected; Nginx itself is not affected. Exploitation is documented in a public GitHub security advisory (GHSA-66m6-27r9-77vm) with a proof of concept available; the flaw is not yet in CISA KEV, and EPSS assigns a 27.7% probability of exploitation within 30 days (98th percentile).

Do: Upgrade Nginx UI to version 2.0.0-beta.36 or later. Until upgraded, restrict access to the Nginx UI interface (bind to localhost or place it behind a VPN/firewall or authenticated reverse proxy) and treat logrotate configuration entries as untrusted. Review logs and existing logrotate settings for signs of injected or unexpected commands indicating prior exploitation.

Nginx-UI is a web interface to manage Nginx configurations. The Import Certificate feature allows arbitrary write into the system. The feature does not check if the provided user input is a certification/key and allows to write into arbitrary paths in the system. It's possible to leverage the vulnerability into a remote code execution overwriting the config file app.ini. Version 2.0.0.beta.12 fixed the issue.

Nginx-UI is a web interface to manage Nginx configurations. It is vulnerable to arbitrary command execution by abusing the configuration settings. The `Home > Preference` page exposes a list of system settings such as `Run Mode`, `Jwt Secret`, `Node Secret` and `Terminal Start Command`. While the UI doesn't allow users to modify the `Terminal Start Command` setting, it is possible to do so by sending a request to the API. This issue may lead to authenticated remote code execution, privilege escalation, and information disclosure. This vulnerability has been patched in version 2.0.0.beta.9.