Vulnerability Description
When NGINX Ingress Controller is configured with Custom Resource Definitions (CRDs) or Ingress annotations, an injection vulnerability exists in the configuration generator of NGINX Ingress Controller. Multiple user-controllable fields are written into the generated NGINX configuration without sanitization. An authenticated attacker with permission to create or modify these CRDs or annotations may craft values that inject arbitrary NGINX configuration directives. Impact: An authenticated attacker granted write access to NGINX Ingress Controller CRDs or Ingress annotations through the Kubernetes API may be able to inject arbitrary NGINX configuration directives, create or delete files, or disable services. There is no data plane exposure; this is a control plane issue only. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| F5 | Nginx Ingress Controller | >= 3.6.0, <= 3.7.2 |
Related Weaknesses (CWE)
References
- https://my.f5.com/manage/s/article/K000161800MitigationVendor Advisory
FAQ
What is CVE-2026-55723?
CVE-2026-55723 is a vulnerability with a CVSS score of 8.3 (HIGH). When NGINX Ingress Controller is configured with Custom Resource Definitions (CRDs) or Ingress annotations, an injection vulnerability exists in the configuration generator of NGINX Ingress Controller...
How severe is CVE-2026-55723?
CVE-2026-55723 has been rated HIGH with a CVSS base score of 8.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-55723?
Check the references section above for vendor advisories and patch information. Affected products include: F5 Nginx Ingress Controller.