Authentication Bypass by Spoofing in NGINX Open Source and NGINX Plus - CVE-2026-40460
Published: May 14, 2026
Vulnerability identifier: #VU131378
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-40460
CWE-ID: CWE-290
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: F5 Networks
Affected software:
NGINX Open Source
NGINX Plus
NGINX Open Source
NGINX Plus
Detailed vulnerability description
The vulnerability allows a remote attacker to bypass authorization or cause a denial of service.
The vulnerability exists due to authentication bypass by spoofing in the ngx_quic_module module when handling HTTP/3 QUIC traffic. A remote attacker can spoof their source IP address to bypass authorization or cause a denial of service.
There is no control plane exposure; this is a data plane issue only.
How to mitigate CVE-2026-40460
Install security update from vendor's website.