CVE-2026-11311: f5 nginx gateway fabric

Vulnerability summary

CVE-2026-11311 is a high (CVSS 8.6) vulnerability in f5 nginx gateway fabric. EPSS estimates a 0.57% chance of exploitation in the next 30 days, higher than 45.8% of scored vulnerabilities.

Timeline

1. 17-06-2026
   PublishedVulnerability first disclosed.
2. 17-06-2026
   Last modifiedVulnerability information updated.

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.

• CWE-76Improper Neutralization of Equivalent Special ElementsThe product correctly neutralizes certain special elements, but it improperly neutralizes equivalent special elements.
• CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.