CVE-2026-3288: kubernetes ingress-nginx Improper Input Validation

Vulnerability summary

CVE-2026-3288 is a high (CVSS 8.8) Improper Input Validation vulnerability in kubernetes ingress-nginx. EPSS estimates a 0.74% chance of exploitation in the next 30 days, higher than 53.8% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 09-03-2026
   PublishedVulnerability first disclosed.
2. 30-04-2026
   Last modifiedVulnerability information updated.

Description

A security issue was discovered in ingress-nginx where the `nginx.ingress.kubernetes.io/rewrite-target` Ingress annotation can be used to inject configuration into nginx. This can lead to arbitrary code execution in the context of the ingress-nginx controller, and disclosure of Secrets accessible to the controller. (Note that in the default installation, the controller can access all Secrets cluster-wide.)

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.