Improper Neutralization of Equivalent Special Elements in NGINX Gateway Fabric - CVE-2026-11311
Published: June 18, 2026
Vulnerability identifier: #VU134862
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-11311
CWE-ID: CWE-76
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: F5 Networks
Affected software:
NGINX Gateway Fabric
NGINX Gateway Fabric
Detailed vulnerability description
The vulnerability allows a remote user to inject arbitrary NGINX configuration directives.
The vulnerability exists due to improper neutralization of equivalent special elements in the NGINX configuration generator component when rendering user-supplied values from the NginxProxy serverTokens field or the AuthenticationFilter extraAuthArgs field into NGINX configuration templates. A remote user can create or modify these custom resource definitions with crafted values to inject arbitrary NGINX configuration directives.
This is a control plane issue only and affects deployments that use NGINX Plus as the data plane.
How to mitigate CVE-2026-11311
Install security update from vendor's website.