CVE-2026-11311
Description
When NGINX Plus is configured as the data plane for NGINX Gateway Fabric, an injection vulnerability exists in the NGINX configuration generator component of NGINX Gateway Fabric. User-supplied string values from the NginxProxy Custom Resource Definition serverTokens field and the AuthenticationFilter Custom Resource Definition extraAuthArgs field are rendered directly into NGINX configuration templates without sanitization or escaping. An authenticated attacker with permission to create or modify these Custom Resource Definitions may craft values that inject arbitrary NGINX configuration directives. This is a control plane issue; there is no data plane exposure from the vulnerability trigger itself.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Summary dbcve.org
This is a configuration injection vulnerability in NGINX Gateway Fabric's NGINX configuration generator. Authenticated attackers with permissions to create or modify NginxProxy or AuthenticationFilter CRDs can supply specially crafted values in the serverTokens and extraAuthArgs fields that get rendered directly into NGINX config templates without sanitization, enabling injection of arbitrary NGINX directives.
Mitigation
Implement strict input validation and escaping for the serverTokens and extraAuthArgs fields in the CRD controllers before rendering into templates, using allowlist validation where possible.