CVE-2026-77180: F5 Nginx Ingress Controller

High severity, CVSS 8.3. EPSS: 0.5% chance of exploitation in the next 30 days.

When NGINX Ingress Controller is configured with 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 annotations may craft values that inject arbitrary NGINX configuration directives. Impact: An authenticated attacker granted write access to NGINX Ingress Controller 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

• F5 Nginx Ingress Controller: from 5.0.0, before 5.6.0 (fixed in 5.6.0); from 2026-lts-r1, before 2026-lts-r5 (fixed in 2026-lts-r5)

Published 2026-09-02. Last modified 2026-09-03.