NGINX
CVE-2026-55723: NGINX Ingress Controller vulnerability
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.
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| NGINX Ingress Controller 5.0 | 5.5.2 or later |
| NGINX Ingress Controller 2026-lts-r1 | 2026-lts-r3 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
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.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 12 Oct 2026.