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 4.0
- 5.5
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P - CVSS 3.1
- 8.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 7% of CVEs (scores of 2026-10-26)
- CWE
- CWE-1385
- Published
- Modified
- Record from
- the NVD, synced
Affected
- nginxui:nginx_ui
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-78mf-482w-62qj | Go | github.com/0xJacky/Nginx-UI | <1.9.10-0.20260316053337-1a9cd29a3082 | 1.9.10-0.20260316053337-1a9cd29a3082 |
| GO-2026-5210 | Go | github.com/0xJacky/Nginx-UI | <1.9.10-0.20260316053337-1a9cd29a3082 | 1.9.10-0.20260316053337-1a9cd29a3082 |