Cloudflare runtime exposes five agent isolation flaws

Check Point Research found five vulnerabilities in workerd, the open-source runtime beneath Cloudflare Workers and Code Mode; Cloudflare rated two Critical, and the chain created sandbox-escape and cross-tenant data-exposure risk. The research report says managed Workers was patched in production and self-hosted workerd or Code Mode operators should update to v1.20260619.1. Teams extending agent-harness policy into the runtime should treat the sandbox version as part of the AI control plane, not as an invisible platform detail.