Vulnerability · Published Jul 15, 2026 · Assigned by f5
CVE-2026-55723NGINX Ingress Controller vulnerability
High 8.3
In plain English
A high-severity security flaw in NGINX Ingress Controller from F5. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 44% of all known vulnerabilities).
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| F5 | NGINX Ingress Controller | 5.0.0 – before 5.5.22026-lts-r1 – before 2026-lts-r3 |
Weakness: CWE-76 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L
References
- https://my.f5.com/manage/s/article/K000161800 vendor-advisory, patch