CVE-2026-34403

Nginx UI is a web user interface for the Nginx web server. Prior to version 2.3.5, all WebSocket endpoints in nginx-ui use a gorilla/websocket Upgrader with CheckOrigin unconditionally returning true, allowing Cross-Site WebSocket Hijacking (CSWSH). Combined with the fact that authentication tokens are stored in browser cookies (set via JavaScript without HttpOnly or explicit SameSite attributes), a malicious webpage can establish authenticated WebSocket connections to the nginx-ui instance when a logged-in administrator visits the attacker-controlled page. Version 2.3.5 patches the issue.

CVSS v3 8.1 HIGH

8.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.5	Product Release Notes
https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-78mf-482w-62qj	Exploit Mitigation Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:nginxui:nginx_ui:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-04-20 21:16

Updated : 2026-06-17 10:39

NVD link : CVE-2026-34403

Mitre link : CVE-2026-34403

CVE.ORG link : CVE-2026-34403

JSON object : View

Products Affected

nginxui

nginx_ui

CWE

CWE-1385

Missing Origin Validation in WebSockets

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