Origin validation error in nginx-ui - CVE-2026-34403
Published: April 21, 2026 / Updated: April 21, 2026
Vulnerability identifier: #VU126634
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Amber
CVE-ID: CVE-2026-34403
CWE-ID: CWE-346
Exploitation vector: Remote access
Exploit availability:
Public exploit is available
Vendor: Nginx UI
Affected software:
nginx-ui
nginx-ui
Detailed vulnerability description
The vulnerability allows a remote attacker to compromise the target system.
The vulnerability exists due to the Cross-Site WebSocket Hijacking (CSWSH) issue within missing origin validation on all WebSocket endpoints. A remote attacker can gain access to sensitive information on the system, leading to arbitrary code execution.
How to mitigate CVE-2026-34403
Install updates from vendor's website.