Kube-router is a turnkey solution for Kubernetes networking. Prior to version 2.8.0, Kube-router's proxy module does not validate externalIPs or loadBalancer IPs before programming them into the node's network configuration. Version 2.8.0 contains a patch for the issue. Available workarounds include enabling DenyServiceExternalIPs feature gate, deploying admission policy, restricting service creation RBAC, monitoring service changes, and applying BGP prefix filtering.
https://github.com/cloudnativelabs/kube-router/security/advisories/GHSA-phqm-jgc3-qf8g
https://github.com/cloudnativelabs/kube-router/releases/tag/v2.8.0
https://github.com/cloudnativelabs/kube-router/commit/a1f0b2eea3ee0f66b9a5b5c49dcb714619ccd456