CVE-2026-34403
Published: Apr 20, 2026
Modified: Apr 21, 2026
Description
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.
| Vendor | Product | Versions |
|---|---|---|
0xJacky | nginx-ui | affected < 2.3.5 |
Weaknesses (CWE)
References
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