# CVE-2026-11311: F5 NGINX Gateway Fabric configuration injection in CRD fields

Source: https://junglewise.ai/threats/cve-2026-11311-f5-nginx-gateway-fabric-configuration-injection-in-crd-fields  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-17. Updated: 2026-06-20  
License: CC BY 4.0 with a link back

CVE-2026-11311 · Severity: high · CVSS 8.1 · Published 2026-06-17

NGINX Gateway Fabric is a tool used to manage network traffic for modern applications. A security flaw in its configuration generator allows users with specific administrative permissions to inject unauthorized commands into the system's underlying configuration. This could allow an attacker to bypass security controls or gain unauthorized access to sensitive data managed by the gateway.

Technologies: [F5 Nginx Gateway Fabric](https://junglewise.ai/threats/technologies/nginx-gateway-fabric). Vendors: [F5](https://junglewise.ai/threats/vendors/f5).

## Quick answers

**Is CVE-2026-11311 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-11311 being exploited in the wild.

**How severe is CVE-2026-11311?** High severity, with a CVSS score of 8.1, published 17 June 2026.

**Which products and versions are affected?** F5 Nginx Gateway Fabric 2.5.0 to 2.6.4.

**Is there a fix for CVE-2026-11311?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-11311 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-11311?** Check whether you run F5 Nginx Gateway Fabric at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An injection vulnerability exists in the NGINX configuration generator component of NGINX Gateway Fabric when NGINX Plus is used as the data plane. The root cause is the lack of sanitization or escaping for user-supplied string values in the 'serverTokens' field of the NginxProxy Custom Resource Definition (CRD) and the 'extraAuthArgs' field of the AuthenticationFilter CRD. These values are rendered directly into NGINX configuration templates. An authenticated attacker with permissions to create or modify these CRDs can inject arbitrary NGINX configuration directives. While this is a control plane issue, it allows for significant manipulation of the gateway's behavior. The vulnerability is addressed in version 2.6.4.

## Affected products

- F5 NGINX Gateway Fabric 2.5.0 to 2.6.4

## Timeline

- 2026-06-17: disclosed
- 2026-06-17: advisory

## References

- [https://my.f5.com/manage/s/article/K000161611](https://my.f5.com/manage/s/article/K000161611)

## Related threats

- [F5 NGINX Gateway Fabric configuration injection in NginxProxy CRD](https://junglewise.ai/threats/cve-2026-50107-f5-nginx-gateway-fabric-configuration-injection-in-nginxproxy-crd)
- [F5 NGINX Gateway Fabric DoS in GRPCRoute backendRef filters](https://junglewise.ai/threats/cve-2026-32682-f5-nginx-gateway-fabric-dos-in-grpcroute-backendref-filters)
- [F5 NGINX memory over-read in SCGI and uWSGI modules](https://junglewise.ai/threats/cve-2026-42946-f5-nginx-memory-over-read-in-scgi-and-uwsgi-modules)
- [F5 NGINX heap buffer over-read in ngx_http_charset_module](https://junglewise.ai/threats/cve-2026-42934-f5-nginx-heap-buffer-over-read-in-ngx-http-charset-module)
- [F5 NGINX Open Source header injection in HTTP/2 proxying](https://junglewise.ai/threats/cve-2026-42926-f5-nginx-open-source-header-injection-in-http-2-proxying)