EUVD-2026-27135
GHSA-h27v-ph7w-m9fp
Severity by source
AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Primary rating from GitHub Advisory · only source for this CVE.
CVSS VectorGitHub Advisory
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
2DescriptionGitHub Advisory
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.
AnalysisAI
Unauthenticated attackers can hijack the administrator account during nginx-ui's first-run installation window by claiming the /api/install endpoint before legitimate operators. This race-condition vulnerability in nginx-ui versions 2.0.0 through 2.3.7 bypasses authentication controls entirely, allowing complete instance takeover with attacker-controlled credentials. The request-encryption mechanism protects only transit confidentiality, not authorization. Attack complexity is rated HIGH due to the narrow time window between deployment and legitimate setup completion. EPSS data unavailable; no CISA KEV listing or public POC identified at time of analysis, but exploitation requires only standard HTTP tools and timing.
Technical ContextAI
Nginx UI (CPE: cpe:2.3:a:0xjacky:nginx-ui) is a web-based management interface for the Nginx web server. The vulnerability stems from CWE-306 (Missing Authentication for Critical Function) in the installation initialization flow. The /api/install endpoint, designed for first-run setup, lacks authentication controls and accepts installation requests from any network-reachable source. While the implementation uses request encryption to protect credentials in transit, this cryptographic layer only ensures confidentiality-it does not verify that the requester is authorized to configure the instance. This design flaw creates a race condition where the first client to successfully invoke the endpoint gains permanent administrative access. The vulnerability exists in the initialization logic that transitions the application from unconfigured to production state without validating the legitimacy of the setup request.
RemediationAI
Upgrade immediately to nginx-ui version 2.3.8 or later, released by the vendor to address this vulnerability (https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.8). Version 2.3.8 implements authentication controls on the /api/install endpoint to prevent unauthorized setup requests. For environments unable to upgrade immediately, implement network-level access controls to restrict the /api/install endpoint to trusted IP addresses during initial deployment-configure firewall rules or reverse proxy ACLs to block external access until setup is complete, then remove restrictions. Deploy new instances in isolated network segments unreachable from the internet during setup, completing configuration before exposing to production networks; this mitigation adds operational complexity to deployment pipelines but eliminates the race-condition window. Monitor authentication logs after any deployment to verify the configured administrator credentials match expected values; unauthorized account creation would indicate successful exploitation requiring immediate instance rebuild. For cloud or container deployments, use infrastructure-as-code to automate configuration immediately post-provisioning, minimizing the window of exposure to milliseconds rather than human-time intervals.
The ngx_http_parse_chunked function in http/ngx_http_parse.c in nginx 1.3.9 through 1.4.0 allows remote attackers to cau
A critical vulnerability in Kubernetes ingress-nginx controller allows unauthenticated attackers with pod network access
nginx 0.8.41 through 1.4.3 and 1.5.x before 1.5.7 allows remote attackers to bypass intended restrictions via an unescap
An issue was discovered on GL.iNet devices before version 4.5.0. Rated critical severity (CVSS 9.8), this vulnerability
Nginx versions since 0.5.6 up to and including 1.13.2 are vulnerable to integer overflow vulnerability in nginx range fi
The resolver in nginx before 1.8.1 and 1.9.x before 1.9.10 allows remote attackers to cause a denial of service (invalid
Kubernetes ingress-nginx contains a configuration injection vulnerability via the mirror-target and mirror-host Ingress
A security issue was discovered in ingress-nginx https://github.com/kubernetes/ingress-nginx where the `auth-url` Ingres
A security issue was discovered in ingress-nginx https://github.com/kubernetes/ingress-nginx where the `auth-tls-match-c
Roxy-WI is a web interface for managing Haproxy, Nginx, Apache and Keepalived servers. Rated critical severity (CVSS 9.8
The STARTTLS implementation in mail/ngx_mail_smtp_handler.c in the SMTP proxy in nginx 1.5.x and 1.6.x before 1.6.1 and
Heap buffer overflow in NGINX Plus and NGINX Open Source ngx_http_rewrite_module allows remote attackers to crash worker
Same technique Authentication Bypass
View allShare
External POC / Exploit Code
Leaving vuln.today